Poxvirus vectors encoding hiv antigens, and methods of use thereof

ABSTRACT

Poxvirus vectors encoding a synthetic HIV envelope antigen and other HIV antigens, as well as compositions containing such poxvirus vectors and uses of such poxvirus vectors as vaccines to provide improved immunity against HIV, are provided. Also provided are vaccine combinations containing the disclosed poxvirus vectors, adenovirus vectors encoding one or more HIV antigens, and one or more isolated HIV antigenic polypeptides, and methods of using the vaccine combinations to provide improved immunity against HIV.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is entitled to priority pursuant to 35 U.S.C. § 119(e)to U.S. Provisional Patent Application No. 62/520,079, filed Jun. 15,2017, the disclosure of which is incorporated by reference herein in itsentirety.

REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY

This application contains a sequence listing, which is submittedelectronically via EFS-Web as an ASCII formatted sequence listing with afile name “688097-331WO Sequence Listing”, creation date of Jun. 7,2017, and having a size of 174.4 KB. The sequence listing submitted viaEFS-Web is part of the specification and is herein incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

Human Immunodeficiency Virus (HIV) affects millions of people worldwide,and the prevention of HIV through an efficacious vaccine remains a veryhigh priority, even in an era of widespread antiretroviral treatment.HIV-1 is the most common and pathogenic strain of the virus, with morethan 90% of HIV/AIDS cases deriving from infection with HIV-1 group M.The M group is subdivided further into clades or subtypes. Anefficacious vaccine ideally would be capable of eliciting both potentcellular responses and broadly neutralizing antibodies capable ofneutralizing HIV-1 strains from different clades.

The high genetic variability of HIV-1 makes the development of a HIV-1vaccine an unprecedented challenge. In order to improve coverage ofpotential T-cell epitopes, and improve cellular responses, “mosaic”HIV-1 Gag, Pol and Env antigens, derived from HIV Group Antigen (Gag),Polymerase (Pol), and Envelope (Env) proteins, were described by othersand developed in an attempt to provide maximal coverage of potentialT-cell epitopes (e.g., Barouch et al, Nat Med 2010, 16: 319-323). Themosaic antigens are similar in length and domain structure to wild-type,naturally occurring HIV-1 antigens.

For example, mosaic HIV antigens described and used in vaccines includethose described in Barouch et al, supra, and WO 2010/059732 such as:

(a) Gag mosaic antigens including:

-   -   (a)(i) a first mosaic Gag sequence (“mos1Gag”) having the amino        acid sequence as set forth herein in SEQ ID NO: 1, and    -   (a)(ii) a second mosaic Gag sequence (“mos2Gag”) having the        amino acid sequence as set forth herein in SEQ ID NO: 2;

(b) Pol mosaic antigens including:

-   -   (b)(i) a first mosaic Pol sequence (“mos1Pol”) having the amino        acid sequence as set forth herein in SEQ ID NO: 3, and    -   (b)(ii) a second mosaic Pol sequence (“mos2Pol”) having the        amino acid sequence as set forth herein in SEQ ID NO: 4; and

(c) Env mosaic antigens including:

-   -   (c)(i) a first mosaic Env sequence (“mos1Env”) having the amino        acid sequence as set forth herein in SEQ ID NO: 5, and    -   (c)(ii) a second mosaic Env sequence (“mos2Env”) having the        amino acid sequence as set forth herein in SEQ ID NO: 6.

Sequences encoding these antigens have been cloned in vectors, forexample, such as recombinant adenoviral vectors, e.g., recombinantadenovirus serotype 26 (rAd26), and these recombinant vectors werepreviously used as vaccines to generate immune responses to the antigens(see e.g. Barouch et al, supra; and WO 2010/059732). For example, themos1Gag and mos1Pol mosaic antigen sequences are typically combined intoa fusion protein of Gag and Pol (“mos1GagPol”), and the coding sequenceof which is cloned into a first Ad26 vector (“rAd26.mos1GagPol”); andthe mos2Gag and mos2Pol antigen sequences are combined into anotherfusion protein of Gag and Pol (“mos2GagPol”), and the coding sequence ofwhich is cloned into a second Ad26 vector (“rAd26.mos2GagPol”).Constructs encoding mos1Env and mos2Env are typically cloned intoseparate Ad26 vectors (“rAd26.mos1Env” and “rAd26.mos2Env”,respectively).

A set of such mosaic antigens as described above gives good globalcoverage of Group M HIV-1 isolates, where rAd26 vectors encoding mosaic1 antigen sequences (e.g., rAd26.mos1GagPol and rAd26.mos1Env) favorclade B and CRF01 HIV-1 subtypes, and rAd26 vectors encoding mosaic 2antigen sequences (e.g., rAd26.mos2GagPol and rAd26.mos2Env) favor cladeC strains. Mosaic HIV-1 Gag, Pol, and Env antigens expressed in rAd26vectors can be used to improve both the breadth and depth ofantigen-specific T-lymphocyte responses in rhesus monkeys, withoutcompromising the magnitude of both cellular and humoral responses whencompared with consensus or natural sequence HIV-1 antigens (Barouch etal, supra; and WO 2010/059732).

However, upon further development efforts on the vaccine componentsdescribed above, it was found that rAd26.mos2Env showed non-optimal cellsurface expression and immune response in non-human primates, butmoreover displayed a hitherto unreported, unexpected and unpredictablenon-optimal genetic stability during the manufacturing process ascompared to the other rAd26 vectors, such as rAd26.mos1Env. Thus,vaccines containing rAd26.mos2Env may result in non-optimal immuneresponses against Clade C HIV-1 subtypes, since the mos2Env mosaicantigen favors clade C HIV-1 strains. Accordingly, there is a need foran alternative to the mos2Env antigen in vaccines against HIV that canbe used to induce improved immune responses against HIV-1 clade C.

Poxvirus vectors, such as Modified Vaccinia virus Ankara (MVA), can beused to encode antigens of interest for vaccination purposes. There is aneed in the art for poxvirus vectors encoding novel combinations of HIVantigens.

BRIEF SUMMARY OF THE INVENTION

The invention relates to synthetic human immunodeficiency virus (HIV)envelope proteins that have improved cell surface expression and geneticstability as compared to the previously described mos2Env antigen and anovel poxvirus vector comprising nucleic acid sequence encoding thesynthetic HIV envelope proteins. The invention also relates tocompositions and methods of using such novel poxvirus vectors comprisingnucleic acid sequence encoding the synthetic HIV envelope proteins toinduce increased immune responses against HIV-1, particularly HIV-1clade C and B, preferably when used in combination with other HIVantigens.

In particular aspects, the invention relates to poxvirus vectors,preferably Modified Vaccinia virus Ankara (MVA) vectors, comprisingnucleic acid encoding the synthetic HIV envelope protein and preferablycomprising a nucleic acid sequence encoding further HIV antigens.

In one general aspect, the invention relates to a nucleic acid encodinga synthetic HIV envelope protein comprising the amino acid sequence ofSEQ ID NO: 8. The synthetic HIV envelope protein can further comprise asignal sequence, for instance a signal sequence having the amino acidsequence selected from the group consisting of SEQ ID NOs: 9-12. In oneembodiment, the signal sequence has the amino acid sequence of SEQ IDNO: 9.

In certain embodiments, the synthetic HIV envelope protein furthercomprises a transmembrane domain, preferably a transmembrane domainhaving the amino acid sequence of SEQ ID NO: 13. In certain embodiments,the synthetic HIV envelope protein further comprises a fragment of acytoplasmic domain, preferably a fragment of a cytoplasmic domaincomprising the amino acid sequence of SEQ ID NO: 14, or the N-terminalamino acids 1-4 thereof (i.e., NRVR). In embodiments wherein thesynthetic HIV envelope protein further comprises a transmembrane domainand a fragment of a cytoplasmic domain, it is preferred that the proteinalso comprises the amino acid sequence of SEQ ID NO: 37, which is fusedto the carboxyl-terminus (C-terminus) of SEQ ID NO: 8 and theamino-terminus (N-terminus) of the transmembrane region.

In a most preferred embodiment, the invention relates to a poxvirusvector comprising a nucleic acid sequence encoding a synthetic HIVenvelope protein comprising the amino acid sequence of SEQ ID NO: 17,SEQ ID NO: 18, or aa 1-686 of SEQ ID NO: 19. Most preferably thesynthetic HIV envelope protein encoded by the nucleic acid comprises orconsists of the amino acid sequence of SEQ ID NO: 18.

In preferred embodiments, the poxvirus vector comprises a nucleic acidencoding a synthetic HIV envelope protein as described above, and atleast one additional HIV antigen. In a preferred embodiment, thepoxvirus vector is a Modified Vaccinia virus Ankara (MVA) vector. Mostpreferably the MVA vector comprises MVA-BN or derivatives thereof.

In one preferred embodiment, the poxvirus vector comprises (a) nucleicacid encoding a first HIV envelope (Env) antigen comprising the aminoacid sequence of SEQ ID NO: 18, and preferably further comprises nucleicacid encoding: (b) a second HIV Env antigen different from the first HIVEnv antigen; (c) a third antigen and fourth antigen, being two differentHIV Gag antigens; and (d) a fifth antigen and sixth antigens, being twodifferent HIV Pol antigens. In certain preferred embodiments, (b) thesecond HIV Env antigen comprises the amino acid sequence of SEQ ID NO:5; (c) the third and fourth antigens comprise the amino acid sequence ofSEQ ID NO: 1 and SEQ ID NO: 2, respectively; and (d) the fifth and thesixth antigens comprise the amino acid sequence of SEQ ID NO: 3 and SEQID NO: 4, respectively. In certain embodiments, the third and fifthantigens are fused into a first Gag-Pol fusion antigen, preferablycomprising SEQ ID NO: 28; and the fourth and sixth antigens are fusedinto a second Gag-Pol fusion antigen, preferably comprising SEQ ID NO:29. In certain particular embodiments, the first HIV Env antigen isencoded by SEQ ID NO: 41. In one or more particular embodiments, thesecond HIV Env antigen is encoded by SEQ ID NO: 39; the first Gag-Polfusion antigen is encoded by SEQ ID NO: 38; and the second Gag-Polfusion antigen is encoded by SEQ ID NO: 40.

In embodiments wherein the poxvirus vector is an MVA vector, such as anMVA vector comprising MVA-BN or derivatives thereof, the first Gag-Polfusion antigen and the second Env antigen are preferably inserted intointergenic region (IGR) 44/45 of the MVA genome, and the second Gag-Polfusion antigen and the first Env antigen are preferably inserted intoIGR 88/89 of the MVA genome. More preferably, the first Gag-Pol fusionantigen and the second Gag-Pol fusion antigens are each under control ofa separate promoter, preferably a Pr13.5 promoter, and the first Envantigen and the second Env antigen are each under control of a separatepromoter, preferably a PrHyb promoter.

Another general aspect of the invention relates to a composition,preferably a vaccine composition, comprising an immunogenicallyeffective amount of a poxvirus vector comprising a nucleic acid sequenceencoding a synthetic HIV envelope protein according to an embodiment ofthe invention and preferably further comprising a nucleic acid sequenceencoding one or more additional HIV antigens, and a carrier, wherein thenucleic acid encoding the synthetic HIV envelope protein is operablylinked to a promoter sequence. In one embodiment, the compositionfurther comprises an adenovirus vector, preferably an adenovirus 26vector, encoding a synthetic HIV envelope protein comprising the aminoacid sequence of SEQ ID NO: 18. In certain embodiments, the compositioncomprises a poxvirus vector, preferably an MVA vector, encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18, and preferably encoding further HIV antigens. In certainembodiments, the compositions of the invention further compriseadditional expression vectors encoding additional HIV antigens and/orisolated HIV antigenic polypeptide.

In another general aspect, the invention relates to a vaccinecombination for inducing an immune response against a humanimmunodeficiency virus (HIV) in a subject in need thereof. In oneembodiment, the vaccine combination comprises:

-   -   (a) a first vaccine composition comprising an immunogenically        effective amount of a vector, preferably a poxvirus vector, more        preferably an MVA vector, encoding (i) a first HIV envelope        (Env) protein being a synthetic HIV envelope protein comprising        the amino acid sequence of SEQ ID NO: 18 and preferably further        comprising nucleic acid encoding: (ii) a second HIV Env antigen        different from the first HIV Env antigen; (iii) a third antigen        and a fourth antigen, being two different HIV Gag antigens;        and (iv) a fifth antigen and a sixth antigen, being two        different HIV Pol antigens; and at least one of:    -   (b) (i) a second vaccine composition comprising an        immunogenically effective amount of one or more vectors,        preferably one or more adenovirus vectors, more preferably one        or more adenovirus 26 vectors, encoding one or more of the        first, second, third, fourth, fifth, and sixth HIV antigens,        preferably encoding one or more HIV antigens comprising an amino        acid sequence selected from the group consisting of SEQ ID NOs:        1-5, 18, 28, and 29; and/or    -   (b) (ii) a third vaccine composition comprising one or more        polypeptides comprising an immunogenically effective amount of        an isolated HIV antigenic polypeptide, for instance, a        polypeptide comprising residues 30-708 of the amino acid        sequence of SEQ ID NO: 7, and/or a polypeptide comprising        residues 30-724 of SEQ ID NO: 36,        wherein the first composition and the second and/or third        compositions are present in the same composition or in one or        more different compositions.

In one embodiment wherein the vaccine combination comprises a secondvaccine composition, the second vaccine composition comprises one ormore recombinant adenovirus 26 vectors encoding one or more antigenscomprising the amino acid sequences selected from the group consistingof SEQ ID NOs: 1-5, 18, 28, and 29, more preferably comprising two,three, or four recombinant adenovirus 26 vectors together encoding SEQID NOs: 1, 2, 3, 4, 5, and 18.

Yet another general aspect of the invention relates to methods ofinducing an immune response against a human immunodeficiency virus (HIV)in a subject in need thereof, comprising administering to the subject acomposition, such as a vaccine composition, or vaccine combinationaccording to an embodiment of the invention. The invention also relatesto methods of inducing an immune response against an HIV comprisingpriming and boosting the immune response using a composition or avaccine combination according to an embodiment of the invention.

In a particular embodiment, a method of inducing an immune responseagainst a HIV in a subject in need thereof comprises administering tothe subject:

-   -   (a) a first vaccine comprising one or more recombinant        adenovirus vectors, preferably Ad26 vectors, encoding one or        more of SEQ ID NOs: 1, 2, 3, 4, 5, and 18; and    -   (b) a second vaccine comprising a poxvirus vector, preferably an        MVA vector, encoding a first HIV envelope (Env) protein being a        synthetic HIV envelope protein comprising the amino acid        sequence of SEQ ID NO: 18 and preferably encoding further HIV        antigens, preferably a second HIV Env antigen different from the        first HIV Env antigen, a third antigen and a fourth antigen        being two different HIV Gag antigens, and a fifth antigen and        sixth antigen being two different HIV Pol antigens, more        preferably one or more HIV antigens encoding the amino acid        sequences selected from the group consisting of SEQ ID NOs: 1-5,        28, and 29,        wherein the first vaccine is a priming vaccine and the second        vaccine is a boosting vaccine, or wherein the second vaccine is        a priming vaccine and the first vaccine is a boosting vaccine.        In certain embodiments, one or more isolated HIV antigenic        polypeptides preferably comprising an immunogenically effective        amount of an isolated HIV antigenic polypeptide, for example, a        polypeptide comprising residues 30-708 of the amino acid        sequence of SEQ ID NO: 7, and/or a polypeptide comprising        residues 30-724 of SEQ ID NO: 36 are administered to the subject        at about the same time as the boosting vaccine in the same        composition as the boosting vaccine or in a composition separate        from the boosting vaccine.

Another aspect of the invention relates to a cell, preferably anisolated cell, comprising a vector according to an embodiment of theinvention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe invention, will be better understood when read in conjunction withthe appended drawings. It should be understood that the invention is notlimited to the precise embodiments shown in the drawings.

In the drawings:

FIGS. 1A-1C are schematic representations of the structure of HIVenvelope proteins; FIG. 1A shows a full length HIV envelope protein;FIG. 1B shows the structure of a soluble single chain HIV envelopeprotein according to an embodiment of the invention in which thetransmembrane domain (TM) is replaced with a GCN4 trimerization domain,and the furin cleavage site is mutated (sC4); FIG. 1C shows thestructure of a membrane bound HIV envelope protein according to anembodiment of the invention comprising a transmembrane domain and afragment of a cytoplasmic domain (C4D7);

FIG. 2 shows expression levels of the soluble sC1 HIV envelope protein,which is based on the mos2Env mosaic antigen sequence with an additionalC-terminal trimerization domain, and a soluble synthetic HIV envelopeprotein (sC4) according to an embodiment of the invention; expressionwas measured by quantitative Western blot using a polyclonal antibodyagainst gp120; plasmids encoding sC1 or sC4 were transiently expressedtwice, and each transfection was quantified twice by densitometry; thesC1 protein showed very low expression levels compared to the sC4synthetic HIV envelope protein, which showed relatively high expressionlevels;

FIGS. 3A and 3B show the binding of synthetic HIV envelope proteins withmonoclonal antibody 17b (mAb17b) in the presence (light gray) andabsence (dark gray) of soluble CD4 as determined by ELISA assay; FIG. 3Ashows binding of sC1; FIG. 3B shows binding of sC4;

FIG. 4 is an image of a Western blot from a native polyacrylamide gelelectrophoresis of the sC1 protein, and the sC4 synthetic HIV envelopeprotein;

FIG. 5 shows the relative cell surface expression levels of themembrane-bound C1, C1D7, C4 and C4D7 synthetic HIV envelope proteins byFACS analysis of cells expressing these proteins using an anti-gp120polyclonal antibody (GP120), and by binding to broadly neutralizingantibodies PG9 (PG9) and PG16 (PG16) that are quaternary-structuredependent and preferentially bind to correctly folded Env trimer;

FIG. 6 is a graphical representation of the stability of adenovirusvectors containing sequences encoding synthetic HIV envelope proteins ofthe invention including full-length C4 (FLC4), C4D7, and sC4 aftermultiple viral passages; recombinant adenovirus 26 vectors weregenerated in PER.C6 cells; after the initial 3 passages for transfectionand plaque purification, 5 plaques were selected and upscaled for 10passages in T25 format, resulting in a total viral passage number (vpn)of 13; the stability after vpn 3, 5, 10, and 13 as determined by E1transgene cassette polymerase chain reaction (PCR) is shown; forexample, 3/5 means 3 plaques were stable out of 5 plaques tested, and5/5 means 5 plaques were stable out of 5 plaques tested;

FIGS. 7A and 7B show virus neutralization titers against HIV-1 envelopepseudotyped virus particles (EVPs) in a TZM-bl cell-based neutralizationassay in rabbits; log 10-transformed IC₅₀ values of the high-adenoviralvector dosed groups were measured against EVPs VSV-G (negative control)and MW965.26 (Tier 1A clade C) at weeks 1, 8, 14, and 20; each dotrepresents the log 10-transformed IC₅₀ value of an individual rabbit,with the group mean indicated by a horizontal line; HD: Highest Dilutiontested (upper solid line); LD: Lowest Dilution tested (lower solidline); LOB: limit of background, 95 percentile value of compilednegative samples (dotted line); Log 10 IC₅₀ values exceeding the LD orHD threshold were set at the corresponding line; a one-waynon-parametric comparison with control using the Dunn method for jointranking was done for each time point; statistically significantdifferences are indicated in the graphs: *=P<0.05, **=P<0.01, and***=P<0.001; FIG. 7A shows the results with VSV-G (negative control);and FIG. 7B shows the results with MW965.26 (Tier 1A clade C).

FIG. 8 is a graphical representation of inserts into specified locationsof the MVA genome for vector MVA-mBN414; Pr13.5 and PrHyb are promotersequences; IGRs are intergenic regions;

FIGS. 9A, 9B and 9C show immune responses raised in rabbits on day 85following immunization with Ad26.Mos.HIV (abbreviated as Ad26), eitheralone or combined with MVA-mBN414 (abbreviated in FIGS. 9A-9C as “MVA”),clade C gp140 (abbreviated as GP140) or a combination thereof; Males (M)and Females (F) are shown separately; FIGS. 9A and 9B show clade C gp140and Mosaic gp140-specific ELISA titers, respectively; each dotrepresents the log 10-transformed relative potency value (log 10 EU/ml)of an individual rabbit, with group-mean indicated as a horizontal line;ULOQ, upper limit of quantitation (upper solid line), LLOQ lower limitof quantitation (lower solid line), LOB, limit of background (dottedline); all values below the LOB were set at the LOB level; statisticalanalysis consisted of an across sex Tobit model; for the comparison ofgroup 1, 2, and 3, a Tukey correction was applied; statisticallysignificant differences are indicated in the graphs: *P<0.05, **P<0.01,***P<0.001; FIG. 9C shows virus neutralization titers against HIV-1 BaLenvelope pseudotyped virus particles in a TZM-bl cell-basedneutralization assay using rabbit serum; each dot represents the log10-transformed IC₅₀ value of an individual rabbit, with the group meanindicated by a horizontal line; HD: Highest Dilution tested (upper solidline); LD: Lowest Dilution tested (lower solid line); LOB: limit ofbackground, 95 percentile value of compiled negative samples (dottedline); log 10 IC₅₀ values exceeding the LD or HD threshold were set atthe corresponding line; statistical analysis consisted of an across sexTobit model; for the comparison of group 1, 2, and 3, a Tukey correctionwas applied; statistically significant differences are indicated in thegraphs: *P<0.05, **P<0.01, ***P<0.001; and

FIGS. 10A-10E show immune responses raised in mice following prime-only(week 5) or prime-boost (week 7) immunization with Ad26.Mos4.HIV(abbreviated as Ad26) followed by MVA-mBN414 prime-boost or homologousMVA-mBN414 (abbreviated in FIGS. 10A-10E as “MVA”) prime-boost; Groups 1and 2 were primed in week 0 with 2.5×10⁹ or 2.5×10⁸ vp of Ad26.Mos4.HIV,respectively, and boosted in week 5 with 2.8×10⁶ or 2.8×10⁵ TCID₅₀ ofMVA-mBN414, respectively; Groups 3 and 4 were immunized in week 0 andweek 5 with 2.8×10⁶ or 2.8×10⁵ TCID₅₀ of MVA-mBN414, respectively; Group5 (control) was primed with 2.5×10⁹ Ad26.Empty and boosted with 2.8×10⁶TCID₅₀ of MVA-BN-empty; FIGS. 10A and 10B show Mosaic gp140-specificELISA titers; each dot represents the log 10-transformed endpoint titerof an individual mouse, with group-mean indicated as a horizontal line;UD, upper limit of dilution; LD, lowest dilution; all values below theLD were set at the LD level; statistical analysis consisted of an acrossdose Tobit model; statistically significant differences are indicated inthe graphs: *P<0.05, **P<0.01, ***P<0.001; FIGS. 10C-10E showInterferon-gamma (IFN-γ) ELISPOT data at week 7 of the study; each dotrepresents the spot-forming cell (SFC) count per 10⁶ splenocytes of anindividual mouse, with group-mean indicated as a horizontal line; LOD:limit of detection, 95 percentile value of compiled unstimulatedcontrols (dotted line); Env-, Gag- and Pol-specific responses weredetermined by stimulation with the immuno-dominant Env-, Gag- andPol-peptides IHIGPGRAFYTAGDI (SEQ ID NO: 44), AMQMLKETI (SEQ ID NO: 45),and YYDPSKDLI (SEQ ID NO: 46), respectively; statistically significantdifferences are indicated in the graphs: *P<0.05, **P<0.01, ***P<0.001.

DETAILED DESCRIPTION OF THE INVENTION

Various publications, articles and patents are cited or described in thebackground and throughout the specification; each of these references isherein incorporated by reference in its entirety. Discussion ofdocuments, acts, materials, devices, articles or the like which has beenincluded in the present specification is for the purpose of providingcontext for the invention. Such discussion is not an admission that anyor all of these matters form part of the prior art with respect to anyinventions disclosed or claimed.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which this invention pertains. Otherwise, certain terms usedherein have the meanings as set forth in the specification. All patents,published patent applications and publications cited herein areincorporated by reference as if set forth fully herein. It must be notedthat as used herein and in the appended claims, the singular forms “a,”“an,” and “the” include plural reference unless the context clearlydictates otherwise.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, and variations such as“comprises” and “comprising”, will be understood to imply the inclusionof a stated integer or step or group of integers or steps but not theexclusion of any other integer or step or group of integer or step. Whenused herein the term “comprising” can be substituted with the term“containing” or “including” or sometimes when used herein with the term“having”.

When used herein “consisting of” excludes any element, step, oringredient not specified in the claim element. When used herein,“consisting essentially of” does not exclude materials or steps that donot materially affect the basic and novel characteristics of the claim.Any of the aforementioned terms of “comprising”, “containing”,“including”, and “having”, whenever used herein in the context of anaspect or embodiment of the invention can be replaced with the term“consisting of” or “consisting essentially of” to vary scopes of thedisclosure.

As used herein, the conjunctive term “and/or” between multiple recitedelements is understood as encompassing both individual and combinedoptions. For instance, where two elements are conjoined by “and/or”, afirst option refers to the applicability of the first element withoutthe second. A second option refers to the applicability of the secondelement without the first. A third option refers to the applicability ofthe first and second elements together. Any one of these options isunderstood to fall within the meaning, and therefore satisfy therequirement of the term “and/or” as used herein. Concurrentapplicability of more than one of the options is also understood to fallwithin the meaning, and therefore satisfy the requirement of the term“and/or.”

As used herein, “subject” means any animal, preferably a mammal, mostpreferably a human, to who will be or has been administered a vector,composition or vaccine combination according to embodiments of theinvention. The term “mammal” as used herein, encompasses any mammal.Examples of mammals include, but are not limited to, cows, horses,sheep, pigs, cats, dogs, mice, rats, rabbits, guinea pigs, monkeys,humans, etc., more preferably a human.

The invention generally relates to synthetic HIV envelope proteins,nucleic acid and vectors encoding the synthetic HIV envelope proteins,and methods of inducing an immune response against HIV with vectorsencoding the synthetic HIV envelope proteins and optionally encodingfurther HIV antigens, alone or in combination with one or moreadditional vectors encoding one or more additional HIV antigens and/orin combination with one or more additional isolated HIV antigenicpolypeptides.

Human immunodeficiency virus (HIV) is a member of the genusLentivirinae, which is part of the family of Retroviridae. Two speciesof HIV infect humans: HIV-1 and HIV-2. HIV-1 is the most common strainof HIV virus, and is known to be more pathogenic than HIV-2. As usedherein, the terms “human immunodeficiency virus” and “HIV” refer, butare not limited to, HIV-1 and HIV-2.

HIV is categorized into multiple clades with a high degree of geneticdivergence. As used herein, the term “HIV clade” or “HIV subtype” refersto related human immunodeficiency viruses classified according to theirdegree of genetic similarity. There are currently three groups of HIV-1isolates: M, N and O. Group M (major strains) consists of at least tenclades, A through J. Group O (outer strains) can consist of a similarnumber of clades. Group N is a new HIV-1 isolate that has not beencategorized in either group M or 0.

As used herein, the terms “HIV antigenic polypeptide,” “HIV antigenicprotein,” “HIV antigen,” and “HIV immunogen” refer to a polypeptidecapable of inducing an immune response, e.g., a humoral and/or cellularmediated response, against HIV in a subject. The antigenic polypeptideor antigen can be a protein of the HIV, a fragment or epitope thereof,or a combination of multiple HIV proteins or portions thereof that caninduce an immune response or produce an immunity, e.g., protectiveimmunity, against the HIV in a subject.

Preferably, an antigenic polypeptide or antigen is capable of raising ina host a protective immune response, e.g., inducing an immune responseagainst a viral disease or infection, and/or producing an immunity in(i.e., vaccinates) a subject against a viral disease or infection, thatprotects the subject against the viral disease or infection. Forexample, the antigenic polypeptide or antigen can comprise a protein orfragments thereof from Simian Immunodeficiency Virus (SIV) or an HIV,such as the HIV or SIV envelope gp160 protein, the HIV or SIVmatrix/capsid proteins, and the HIV or SIV gag, pol and env geneproducts.

An HIV antigenic polypeptide or antigen can be any HIV-1 or HIV-2antigen or fragment thereof. Examples of HIV antigens include, but arenot limited to gag, pol, and env gene products, which encode structuralproteins and essential enzymes. Gag, pol, and env gene products aresynthesized as polyproteins, which are further processed into multipleother protein products. The primary protein product of the gag gene isthe viral structural protein gag polyprotein, which is further processedinto MA, CA, SP1, NC, SP2, and P6 protein products. The pol gene encodesviral enzymes (Pol, polymerase), and the primary protein product isfurther processed into RT, RNase H, IN, and PR protein products. The envgene encodes structural proteins, specifically glycoproteins of thevirion envelope. The primary protein product of the env gene is gp160,which is further processed into gp120 and gp41. Other examples of HIVantigens include gene regulatory proteins Tat and Rev; accessoryproteins Nef, Vpr, Vif and Vpu; capsid proteins, nucleocapsid proteins,and p24 viral protein.

In certain embodiments, the HIV antigenic polypeptide or antigencomprises an HIV Gag, Env, or Pol antigen, or any antigenic portion orepitope or combination thereof, preferably an HIV-1 Gag, Env, or Polantigen or any antigenic portion or epitope or combination thereof.

HIV antigenic polypeptides can also be mosaic HIV antigens. As usedherein, “mosaic antigen” refers to a recombinant protein assembled fromfragments of natural sequences. Mosaic antigens resemble naturalantigens, but are optimized to maximize the coverage of potential T-cellepitopes found in the natural sequences, which improves the breadth andcoverage of the immune response. Mosaic HIV antigens for use with theinvention are preferably mosaic Gag, Pol, and/or Env antigens, and morepreferably a mosaic HIV-1 Gag, Pol, and/or Env antigens. As used herein,“a mosaic HIV Gag, Pol, and/or Env antigen” specifically refers to amosaic antigen comprising multiple epitopes derived from one or more ofthe Gag, Pol and/or Env polyprotein sequences of HIV.

In one embodiment, a mosaic HIV antigen for use with the invention is amosaic HIV Gag antigen with epitopes derived from the sequences of gaggene products (examples are provided in SEQ ID NOs: 1, 2); a mosaic HIVPol antigen with epitopes derived from the sequences of pol geneproducts (examples are provided in SEQ ID NOs: 3, 4); or a mosaic HIVEnv antigen with epitopes derived from the sequences of env geneproducts (examples are provided in SEQ ID NOs: 5, 6; also the syntheticantigens of the invention, e.g. in SEQ ID NOs: 8, 17, 18, 19, can beconsidered mosaic HIV Env antigens). In certain embodiments, a mosaicHIV antigen for use with the invention comprises a combination ofepitopes derived from sequences of gag, pol, and/or env gene products.Illustrative and non-limiting examples include mosaic Env-Pol antigenswith epitopes derived from the sequences of env and pol gene products;mosaic Gag-Pol antigens with epitopes derived from the sequences of gagand pol gene products (examples are provided in SEQ ID NOs: 28, 29); andmosaic Gag-Env antigens with epitopes derived from the sequences of gagand env gene products. The sequences of gag, pol, and env gene productscan be derived from one or more clades.

Examples of mosaic HIV Gag, Pol and/or Env antigens that can be used inthe invention include those described in, e.g., US20120076812; Barouchet al., Nat Med 2010, 16:319-323; and Barouch et al., Cell 155:1-9,2013, all of which are incorporated herein by reference in theirentirety. Preferably, mosaic HIV Gag, Pol, and/or Env antigens for usewith the present invention include, but are not limited to, mos1Gag (SEQID NO: 1), mos2Gag (SEQ ID NO: 2), mos1Pol (SEQ ID NO: 3), mos2Pol (SEQID NO: 4), mos1Env (SEQ ID NO: 5), mos2Env (SEQ ID NO: 6), mos1GagPol(SEQ ID NO: 28), mos2GagPol (SEQ ID NO: 29), and combinations thereof.

As used herein, each of the terms “HIV envelope protein,” “env protein,”and “Env” refers to a protein that is expressed on the envelope of anHIV virion and enables an HIV to target and attach to the plasmamembrane of HIV infected cells, or a fragment or derivative thereof thatcan induce an immune response or produce an immunity against the HIV ina subject in need thereof. The HIV env gene encodes the precursorprotein gp160, which is proteolytically cleaved into the two matureenvelope glycoproteins, gp120 and gp41. The cleavage reaction ismediated by a host cell protease, furin, at a sequence highly conservedin retroviral envelope glycoprotein precursors. More specifically, gp160trimerizes to (gp160)3 and then undergoes cleavage into the twononcovalently associated gp120 and gp41. Viral entry is subsequentlymediated by a trimer of gp120/gp41 heterodimers. Gp120 is the receptorbinding fragment, and binds to the CD4 receptor on a target cell thathas such a receptor, such as, e.g., a T-helper cell. Gp41, which isnon-covalently bound to gp120, is the fusion fragment and provides thesecond step by which HIV enters the cell. Gp41 is originally buriedwithin the viral envelope, but when gp120 binds to a CD4 receptor, gp120changes its conformation causing gp41 to become exposed, where it canassist in fusion with the host cell. Gp140 is the uncleaved ectodomainof trimeric gp160, i.e., (gp160)3, that has been used as a surrogate forthe native state of the cleaved, viral spike.

According to embodiments of the invention, an “HIV envelope protein” canbe a gp160, gp140, gp120, gp41 protein, combinations, fusions,truncations or derivatives thereof. For example, an “HIV envelopeprotein” can include a gp120 protein noncovalently associated with agp41 protein. It can also include a stabilized trimeric gp140 proteinthat can have or can be modified to include a trimerization domain thatstabilizes trimers of gp140. Examples of trimerization domains include,but are not limited to, the T4-fibritin “foldon” trimerization domain;the coiled-coil trimerization domain derived from GCN4; and thecatalytic subunit of E. coli aspartate transcarbamoylase as a trimertag. An “HIV envelope protein” can also be a truncated HIV envelopeprotein including, but not limited to, envelope proteins comprising aC-terminal truncation in the ectodomain (i.e. the domain that extendsinto the extracellular space), a truncation in the gp41, such as atruncation in the transmembrane domain of gp41, or a truncation in thecytoplasmic domain of gp41. An “HIV envelope protein” can further be aderivative of a naturally occurring HIV envelope protein having sequencemutations, e.g., in the furin cleavage sites, and/or so-called SOSIPmutations.

Preferably, an “HIV envelope protein” is a “synthetic HIV envelopeprotein.” As used herein, the term “synthetic HIV envelope protein”refers to a non-naturally occurring HIV envelope protein that isoptimized to induce an immune response or produce an immunity againstone or more naturally occurring HIV strains in a subject in needthereof. Mosaic HIV Env proteins are examples of synthetic HIV Envproteins, and the invention provides synthetic HIV Env antigens, e.g.the ones comprising SEQ ID NOs: 8, 17, 18, or 19.

As used herein, “TCID₅₀” refers to Tissue Culture Infectious Dose 50given as TCID₅₀. The TCID₅₀ can be determined using various methodsknown to the skilled person such as for example a Tissue CultureInfectious Dose 50 (TCID₅₀) assay. The TCID₅₀ assay is a method fortitrating the infectivity of Modified Vaccinia virus Ankara (MVA)vectors, using 10-fold dilutions in a 96-well format as described inExample 2 of WO 03/053463. The infectivity of a poxvirus such as MVA canbe determined using various methods known to the skilled person such asfor example by a Flow Cytometry based assay or a Tissue CultureInfectious Dose ₅₀ (TCID₅₀) assay. In one exemplary aspect, a titrationof MVA is performed in a TCID₅₀-based assay using 10-fold dilutions in a96-well format. At the endpoint of the assay, infected cells arevisualized using an anti-vaccinia virus antibody and an appropriatestaining solution. Primary CEF cells are prepared and cultivated in RPMIincluding 10% serum and 1% Gentamycin using T-flasks for 2-3 days at agiven density following trypsinization and seeding into 96-well platesat a density of 1×10⁵cells/mL using RPMI with 7% serum. The expectedtiter of the sample dictates the number of 10-fold serial dilutions,which are performed across a deep-well plate from column 1 to e.g. 10using 100 μL for transfer into the next well. Following dilution, 100 μLare seeded per well of 96-well plates. Cells are incubated for 5 days at34-38° C. and 4-6% CO₂ to allow infection and viral replication.

Five days post infection, cells are stained with an MVA specificantibody. For the detection of the specific antibody, a horseradishperoxidase (HRP) coupled secondary antibody is used. The MVA specificantibody can be an anti-vaccinia virus antibody, rabbit polyclonal, oran IgG fraction (Quartett, Berlin, Germany #9503-2057), for example. Thesecondary antibody can be anti-rabbit IgG antibody, or HRP coupled goatpolyclonal (Promega, Mannheim, Germany, # W4011), for example. Thesecondary antibody is visualized using a precipitating TMB substrate.Every well with cells that are positive in the color reaction are markedas positive for the calculation of the TCID₅₀. The titer is calculatedby using the Spearman-Kaerber method of calculation. The data can alsobe represented as a log of virus titer which is the relative differencefor any given time-point from T=0 time-point.

An alternative method for quantification of virus concentration is byviral plaque assay, which is a standard method well known to the skilledperson to determine virus concentration in terms of infectious dose.Briefly, a confluent monolayer of host cells is infected with virus atvarious dilutions and covered with a semi-solid medium. A viral plaqueis formed when a virus infects a cell in the cell monolayer and thenumber of plaques can be counted in combination with the dilution factorto calculate the number of plaque forming units per sample volume(pfu/mL). The pfu/mL represents the number of infective particles withinthe sample. Due to distinct differences in assay methods and principles,TCID₅₀ and pfu/mL or other infectivity assay results are not necessarilyequivalent. For MVA, both methods (TCID₅₀ and viral plaque assay) can beused, and generally the dosage of an MVA vector for clinicaladministration to humans is provided in pfu, or in TCID₅₀. The dosage ofan adenovirus vector can also be given in pfu or TCID₅₀. Foradministration to humans, generally the dosage of an adenovirus vectoris given in viral particles (vp), and concentrations are expressed invp/mL.

Synthetic HIV Envelope Proteins and Coding Sequences Thereof

Embodiments of the invention relate to novel poxvirus vectors,preferably MVA vectors, comprising nucleic acid sequence encodingsynthetic HIV envelope proteins and preferably comprising nucleic acidsequence encoding further HIV antigens.

In one embodiment, a synthetic HIV envelope protein comprises the aminoacid sequence of SEQ ID NO: 8, or SEQ ID NO:8 having one or moremutations selected from the group consisting of (i) I529P, (ii) K480E,and (iii) a combination of EK479-480RRRR, I529P, A471C and T575C. SEQ IDNO: 8 comprises a synthetic mature gp120 and a synthetic truncated gp41without the transmembrane region, nor the cytoplasmic domain. SEQ ID NO:8 is a non-naturally occurring sequence comprised of a chimera ofsequences from the mos2Env mosaic antigen (SEQ ID NO: 6), and other HIVenvelope protein sequences. The sequence of the synthetic Env antigencomprising SEQ ID NO: 8 is optimized to provide broad coverage and anenhanced T-cell response against HIV clade C (as compared to the mos2Envantigen (SEQ ID NO: 6)). In certain embodiments, further amino acids canbe added to SEQ ID NO: 8 or one of its variants defined herein.

In certain embodiments, the synthetic HIV envelope protein furthercomprises a signal sequence. The synthetic HIV envelope protein issynthesized with a signal sequence that is cleaved from the nascentpolypeptide chain during its transport into the lumen of the endoplasmicreticulum (ER). In principle, any known signal sequence could be used.Preferably an HIV Env signal sequence or a variant thereof is used.Different signal sequences have been used in the art for HIV Envproteins (see e.g. WO 2014/107744). In certain embodiments, the signalsequence comprises SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11 or SEQ IDNO: 12. In one preferred embodiment, the signal sequence comprises SEQID NO: 9.

In certain embodiments, the synthetic HIV envelope protein furthercomprises a transmembrane domain. The transmembrane domain anchors thesynthetic HIV envelope protein to the ER membrane, and contributes tomembrane assembly and function of the HIV envelope. Preferably, thetransmembrane domain comprises SEQ ID NO: 13.

In another embodiment, the synthetic HIV envelope protein comprises agp41 having a truncated cytoplasmic domain. The gp41 has an unusuallylong cytoplasmic domain at its carboxyl end, typically about 150 aminoacids (Edwards et al., I Virology, 2002, 76:2683-2691). Truncation ofthe cytoplasmic domain was reported to induce exposure of conservedregions in the ectodomain of HIV-1 Env protein (Id.). The truncatedcytoplasmic domain in a synthetic HIV envelope of the invention canrange from one to about 140 amino acids, such as 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, or 140amino acids of a full-length cytoplasmic domain. In certain embodimentsthe truncated cytoplasmic domain is derived from amino acids 704-862 ofSEQ ID NO: 17 (i.e. from the cytoplasmic domain of the C4 molecule ofthe invention), by truncation after a given amino acid up to theC-terminus. In a preferred embodiment, the synthetic HIV envelopeprotein comprises a truncated cytoplasmic domain having 1 to 10 aminoacids residues, more preferably 4 to 8 amino acid residues, and mostpreferably 7 amino acid residues of an HIV gp41 cytoplasmic domain. Thecytoplasmic domain or fragment thereof of a synthetic HIV envelopeprotein is located C-terminal to the extracellular domain (ectodomain),and when the synthetic HIV envelope protein also comprises atransmembrane domain, the cytoplasmic domain or fragment thereof islocated C-terminal to the transmembrane domain. See, e.g., FIGS. 1A and1C. In a particular embodiment, the synthetic HIV envelope proteincomprises a gp41 with a truncated cytoplasmic domain having the aminoacid sequence of SEQ ID NO: 14 or a fragment thereof, such as residues1-4 thereof (i.e. NRVR). Other truncated cytoplasmic domains have beendescribed and could be used (e.g. Schiernle et al., PNAS 1997;Abrahamyan et al., J Virol 2005).

In embodiments wherein the synthetic HIV envelope protein furthercomprises a transmembrane domain and a fragment of a cytoplasmic domain,it is preferred that the protein also comprises the amino acid sequenceof SEQ ID NO: 37, which contains residues 655-682 of SEQ ID NO: 18,wherein the amino acid sequence of SEQ ID NO: 37 is fused to theC-terminus of SEQ ID NO: 8 and the N-terminus of the transmembranedomain.

In a particularly preferred embodiment of the invention, the syntheticHIV envelope protein further comprises a transmembrane domain, such asthat having the amino acid sequence of SEQ ID NO: 13, and a truncatedcytoplasmic domain or a fragment of a cytoplasmic domain, such as thathaving the amino acid sequence of SEQ ID NO: 14 or residues 1-4 of SEQID NO: 14 (i.e., NRVR). Most preferably, the synthetic HIV envelopeprotein comprises or consists of the amino acid sequence of SEQ ID NO:18, with or without the signal sequence (i.e., amino acid resides 1-29of SEQ ID NO: 18).

In another embodiment, the synthetic HIV envelope protein comprises atrimerization domain that replaces an Env transmembrane region. Thetrimerization domain increases the stability of an Env trimericstructure. Preferably, the synthetic HIV envelope protein comprises agp140 polypeptide that is modified to include a trimerization domainthat stabilizes trimers of gp140. Examples of trimerization domainsinclude, but are not limited to, the T4-fibritin “foldon” trimerizationdomain, such as that comprising the amino acid sequence of SEQ ID NO:16; the coiled-coil trimerization domain derived from GCN4, such as thatcomprising the amino acid sequence of SEQ ID NO: 15; the catalyticsubunit of E. coli aspartate transcarbamoylase as a trimer tag; ormatrillin-based trimerization motifs. If present, the trimerizationdomain typically is located C-terminal to the extracellular domain (seeFIG. 1B). In certain preferred embodiments where the synthetic HIVenvelope protein comprises a trimerization domain, the synthetic HIVenvelope protein comprises the amino acid sequence of SEQ ID NO: 19,with or without the signal sequence (i.e., amino acid residues 1-29 ofSEQ ID NO: 19). These embodiments with trimerization domains are mainlyuseful for soluble ectodomain variants of the synthetic HIV envelopeprotein. In certain embodiments of such soluble variants of theinvention, it is possible to mutate the furin cleavage site (e.g.mutation of Lys to Glu at position 480 in SEQ ID NO: 8) to inactivatethis cleavage site, so that the protein will be a single chain; thiscombines well with a trimerization domain, especially with the GCN4trimerization domain of SEQ ID NO: 19.

Alternative versions of such soluble ectodomain variants of thesynthetic HIV envelope protein without use of trimerization domains arealso embodiments of the invention, and can be prepared from SEQ ID NO: 8by combining mutations that optimize the furin cleavage site (e.g.,replacing the Gly-Lys dipeptide at positions 479-480 by four Argresidues) as well as so-called SOSIP mutations (e.g., I to P mutation atposition 529, and introduction of a disulfide bridge between positions471 and 575 by replacement of the respective Ala and Thr at thosepositions in SEQ ID NO: 8 each with a Cys residue). This yields aprotein having the amino acid sequence of SEQ ID NO: 8 with thefollowing combination of mutations: EK479-480RRRR, I529P, A471C andT575C.

One possible modification to further increase the trimer content of asynthetic HIV envelope protein of the invention (comprising SEQ ID NO:8), is modification of Ile to Pro at position 529. This can be effectivefor both soluble and membrane-bound variants.

Vectors

In one general aspect, the invention relates to vectors comprisingnucleic acid sequence encoding a synthetic HIV envelope protein, andpreferably comprising nucleic acid sequence encoding at least oneadditional HIV antigen. According to embodiments of the invention, thevectors can comprise any of the synthetic HIV envelope proteinsdescribed herein. In a particular embodiment of the invention, thevector is a poxvirus vector, preferably an MVA vector, comprisingnucleic acid sequence encoding a synthetic HIV envelope proteincomprising the amino acid sequence of SEQ ID NO: 8, SEQ ID NO: 17, SEQID NO: 18, or SEQ ID NO: 19, and more preferably SEQ ID NO: 18 or aminoacid residues 30-711 of SEQ ID NO: 18.

According to embodiments of the invention, the nucleic acid sequenceencoding the synthetic HIV envelope protein is operably linked to apromoter, meaning that the nucleic acid is under the control of apromoter. The promoter can be a homologous promoter (i.e., derived fromthe same genetic source as the vector) or a heterologous promoter (i.e.,derived from a different vector or genetic source). Non-limitingexamples of suitable promoters for the adenoviral vectors include thecytomegalovirus (CMV) promoter and the Rous Sarcoma virus (RSV)promoter. Preferably, the promoter is located upstream of the nucleicacid within an expression cassette. An exemplary CMV promoter sequencethat can be operably linked to nucleic acid sequence encoding thesynthetic HIV envelope protein is shown in SEQ ID NO: 24.

Non-limiting examples of suitable promoters for the poxvirus vectorsinclude the 30K promoter, the 13 promoter, the PrS promoter, the PrS5Epromoter, the Pr7.5K, the Pr13.5 long promoter, the PrHyb promoter, the40K promoter, the MVA-40K promoter, the FPV 40K promoter, 30k promoter,the PrSynIIm promoter, and the PrLE1 promoter. Additional promoters arefurther described in WO 2010/060632, WO 2010/102822, WO 2013/189611 andWO 2014/063832, which are incorporated fully by reference herein. Inmore preferred embodiments, the HIV antigens, when incorporated as partof a poxvirus vector according to the invention, are operably linked tothe Pr13.5long promoter (SEQ ID NO: 42) and/or the PrHyb promoter (SEQID NO: 43).

According to embodiments of the invention, a vector can be an expressionvector. Expression vectors include, but are not limited to, vectors forrecombinant protein expression and vectors for delivery of nucleic acidinto a subject for expression in a tissue of the subject, such as aviral vector. Examples of viral vectors suitable for use with theinvention include, but are not limited to adenoviral vectors,adeno-associated virus vectors, poxvirus vectors, MVA vectors, entericvirus vectors, Venezuelan Equine Encephalitis virus vectors, SemlikiForest Virus vectors, Tobacco Mosaic Virus vectors, lentiviral vectors,etc. The vector can also be a non-viral vector. Examples of non-viralvectors include, but are not limited to plasmids, bacterial artificialchromosomes, yeast artificial chromosomes, bacteriophages, etc.

In certain embodiments of the invention, the vector is an adenovirusvector. An adenovirus according to the invention belongs to the familyof the Adenoviridae, and preferably is one that belongs to the genusMastadenovirus. It can be a human adenovirus, but also an adenovirusthat infects other species, including but not limited to a bovineadenovirus (e.g. bovine adenovirus 3, BAdV3), a canine adenovirus (e.g.CAdV2), a porcine adenovirus (e.g. PAdV3 or 5), or a simian adenovirus(which includes a monkey adenovirus and an ape adenovirus, such as achimpanzee adenovirus or a gorilla adenovirus). Preferably, theadenovirus is a human adenovirus (HAdV, or AdHu), or a simian adenovirussuch as chimpanzee or gorilla adenovirus (ChAd, AdCh, or SAdV), or arhesus monkey adenovirus (RhAd). In the invention, a human adenovirus ismeant if referred to as Ad without indication of species, e.g. the briefnotation “Ad26” means the same as HAdV26, which is human adenovirusserotype 26. Also as used herein, the notation “rAd” means recombinantadenovirus, e.g., “rAd26” refers to recombinant human adenovirus 26.

Most advanced studies have been performed using human adenoviruses, andhuman adenoviruses are preferred according to certain aspects of theinvention. In certain preferred embodiments, a recombinant adenovirusaccording to the invention is based upon a human adenovirus. Inpreferred embodiments, the recombinant adenovirus is based upon a humanadenovirus serotype 5, 11, 26, 34, 35, 48, 49, 50, 52, etc. According toa particularly preferred embodiment of the invention, an adenovirus is ahuman adenovirus of serotype 26. Advantages of these serotypes include alow seroprevalence and/or low pre-existing neutralizing antibody titersin the human population, and experience with use in human subjects inclinical trials.

Simian adenoviruses generally also have a low seroprevalence and/or lowpre-existing neutralizing antibody titers in the human population, and asignificant amount of work has been reported using chimpanzee adenovirusvectors (e.g. U.S. Pat. No. 6,083,716; WO 2005/071093; WO 2010/086189;WO 2010085984; Farina et al, 2001, J Virol 75: 11603-13; Cohen et al,2002, J Gen Virol 83: 151-55; Kobinger et al, 2006, Virology 346:394-401; Tatsis et al., 2007, Molecular Therapy 15: 608-17; see alsoreview by Bangari and Mittal, 2006, Vaccine 24: 849-62; and review byLasaro and Ertl, 2009, Mol Ther 17: 1333-39). Hence, in otherembodiments, the recombinant adenovirus according to the invention isbased upon a simian adenovirus, e.g. a chimpanzee adenovirus. In certainembodiments, the recombinant adenovirus is based upon simian adenovirustype 1, 7, 8, 21, 22, 23, 24, 25, 26, 27.1, 28.1, 29, 30, 31.1, 32, 33,34, 35.1, 36, 37.2, 39, 40.1, 41.1, 42.1, 43, 44, 45, 46, 48, 49, 50 orSA7P.

Preferably, the adenovirus vector is a replication deficient recombinantviral vector, such as rAd26, rAd35, rAd48, rAd5HVR48, etc.

In a preferred embodiment of the invention, the adenoviral vectorscomprise capsid proteins from rare serotypes including Ad26. In thetypical embodiment, the vector is an rAd26 virus. An “adenovirus capsidprotein” refers to a protein on the capsid of an adenovirus (e.g., Ad26,Ad35, rAd48, rAd5HVR48 vectors) that is involved in determining theserotype and/or tropism of a particular adenovirus. Adenoviral capsidproteins typically include the fiber, penton and/or hexon proteins. Asused herein a “capsid protein” for a particular adenovirus, such as an“Ad26 capsid protein” can be, for example, a chimeric capsid proteinthat includes at least a part of an Ad26 capsid protein. In certainembodiments, the capsid protein is an entire capsid protein of Ad26. Incertain embodiments, the hexon, penton and fiber are of Ad26.

One of ordinary skill in the art will recognize that elements derivedfrom multiple serotypes can be combined in a single recombinantadenovirus vector. Thus, a chimeric adenovirus that combines desirableproperties from different serotypes can be produced. Thus, in someembodiments, a chimeric adenovirus of the invention could combine theabsence of pre-existing immunity of a first serotype withcharacteristics such as temperature stability, assembly, anchoring,production yield, redirected or improved infection, stability of the DNAin the target cell, and the like.

In certain embodiments the recombinant adenovirus vector useful in theinvention is derived mainly or entirely from Ad26 (i.e., the vector isrAd26). In some embodiments, the adenovirus is replication deficient,e.g., because it contains a deletion in the E1 region of the genome. Foradenoviruses being derived from non-group C adenovirus, such as Ad26 orAd35, it is typical to exchange the E4-orf6 coding sequence of theadenovirus with the E4-orf6 of an adenovirus of human subgroup C such asAd5. This allows propagation of such adenoviruses in well-knowncomplementing cell lines that express the E1 genes of Ad5, such as forexample 293 cells, PER.C6 cells, and the like (see, e.g. Havenga, etal., 2006, J Gen Virol 87: 2135-43; WO 03/104467). However, suchadenoviruses will not be capable of replicating in non-complementingcells that do not express the E1 genes of Ad5.

The preparation of recombinant adenoviral vectors is well known in theart. Preparation of rAd26 vectors is described, for example, in WO2007/104792 and in Abbink et al., (2007) Virol 81(9): 4654-63. Exemplarygenome sequences of Ad26 are found in GenBank Accession EF 153474 and inSEQ ID NO: 1 of WO 2007/104792. Examples of vectors useful for theinvention for instance include those described in WO2012/082918, thedisclosure of which is incorporated herein by reference in its entirety.

Typically, a vector useful in the invention is produced using a nucleicacid comprising the entire recombinant adenoviral genome (e.g., aplasmid, cosmid, or baculovirus vector). Thus, the invention alsoprovides isolated nucleic acid molecules that encode the adenoviralvectors of the invention. The nucleic acid molecules of the inventioncan be in the form of RNA or in the form of DNA obtained by cloning orproduced synthetically. The DNA can be double-stranded orsingle-stranded.

The adenovirus vectors useful in the invention are typically replicationdeficient. In these embodiments, the virus is rendered replicationdeficient by deletion or inactivation of regions critical to replicationof the virus, such as the E1 region. The regions can be substantiallydeleted or inactivated by, for example, inserting a gene of interest,such as a gene encoding a synthetic HIV envelope protein (usually linkedto a promoter), or a gene encoding an HIV antigenic polypeptide (usuallylinked to a promoter) within the region. In some embodiments, thevectors of the invention can contain deletions in other regions, such asthe E2, E3 or E4 regions, or insertions of heterologous genes linked toa promoter within one or more of these regions. For E2- and/orE4-mutated adenoviruses, generally E2- and/or E4-complementing celllines are used to generate recombinant adenoviruses. Mutations in the E3region of the adenovirus need not be complemented by the cell line,since E3 is not required for replication.

A packaging cell line is typically used to produce sufficient amounts ofadenovirus vectors for use in the invention. A packaging cell is a cellthat comprises those genes that have been deleted or inactivated in areplication deficient vector, thus allowing the virus to replicate inthe cell. Suitable packaging cell lines for adenoviruses with a deletionin the E1 region include, for example, PER.C6, 911, 293, and E1 A549.

In a preferred embodiment of the invention, the vector is an adenovirusvector, and more preferably a rAd26 vector, most preferably a rAd26vector with at least a deletion in the E1 region of the adenoviralgenome, e.g. such as that described in Abbink, J Virol, 2007. 81(9): p.4654-63, which is incorporated herein by reference. Typically, thenucleic acid sequence encoding the synthetic HIV envelope protein and/orother HIV antigens is cloned into the E1 and/or the E3 region of theadenoviral genome.

In a preferred aspect of the invention, the vector encoding thesynthetic HIV antigen described herein is a poxvirus vector. In aparticularly preferred aspect, the vector is a Modified Vaccinia virusAnkara (MVA) vector. In additional preferred embodiments, the MVA virusvector is MVA-BN or derivatives thereof.

MVA has been generated by more than 570 serial passages on chickenembryo fibroblasts of the dermal vaccinia strain Ankara (Chorioallantoisvaccinia virus Ankara virus, CVA; for review see Mayr et al. (1975)Infection 3, 6-14) that was maintained in the Vaccination Institute,Ankara, Turkey for many years and used as the basis for vaccination ofhumans. The attenuated CVA-virus MVA (Modified Vaccinia Virus Ankara)was obtained by serial propagation (more than 570 passages) of the CVAon primary chicken embryo fibroblasts (CEF).

However, due to the often severe post-vaccination complicationsassociated with vaccinia viruses, there were several attempts togenerate a more attenuated, safer vaccine. As a result of the passagingused to attenuate MVA, there are a number of different strains orisolates, depending on the number of passages conducted in CEF cells.Strains of MVA having enhanced safety profiles for the development ofsafer products, such as vaccines or pharmaceuticals, have beendeveloped, for example by Bavarian Nordic. MVA was further passaged byBavarian Nordic and is designated MVA-BN. A representative sample ofMVA-BN was deposited on Aug. 30, 2000 at the European Collection of CellCultures (ECACC) under Accession No. V00083008. MVA-BN is furtherdescribed in WO 02/42480 (see also e.g., U.S. Pat. Nos. 6,761,893 and6,913,752 and US 2003/0206926) and WO 03/048184 (US 2006/0159699), whichare incorporated by reference herein in their entireties. MVA as well asMVA-BN lacks approximately 15% (31 kb from six regions) of the genomecompared with ancestral CVA virus. The deletions affect a number ofvirulence and host range genes, as well as the gene for Type A inclusionbodies.

In various embodiments, the MVA or MVA used for generating therecombinants suitable for the present invention are MVA-572, MVA-575,MVA-1721, MVA as deposited as ATCC® VR-1SO8™, MVA as deposited as ATCC®VR-1566™, ACAM3000 MVA, MVA-BN or any similarly attenuated MVA strain.In preferred embodiments, the MVA used for generating the recombinantsare MVA-575, MVA as deposited as ATCC® VR-1SO8™, MVA as deposited asATCC® VR-1566™, ACAM3000 MVA and MVA-BN. More preferably the MVA usedfor generating the recombinants is MVA-BN.

MVA-572 was deposited at the European Collection of Animal Cell Cultures(ECACC, Vaccine Research and Production Laboratory, Public HealthLaboratory Service, Centre for Applied Microbiology and Research, PortonDown, Salisbury, Wiltshire SP4 OJG, United Kingdom) with the depositionnumber ECACC V94012707 on Jan. 27, 1994. MVA-575 was deposited underECACC V00120707 on Dec. 7, 2000. Acam3000 MVA was deposited at theAmerican Type Culture Collection (ATCC) under Accession No.: PTA-5095 onMar. 27, 2003 (American Type Culture Collection, 10801 University Blvd.,Manassas, Va. 20110-2209, USA). MVA-1721 was deposited as CNCM 1721 atthe Collection Nationale de Cultures de Microorganisms, InstitutePasteur. MVA-BN was deposited on Aug. 30, 2000 at the ECACC under numberV00083008. MVA-BN has been described in WO 02/042480.

Also encompassed by the invention are derivatives or variants of any ofthe MVA viruses or MVA-BN described herein. “Derivatives” or “variants”of MVA or MVA-BN refer to MVA or MVA-BN viruses exhibiting essentiallythe same replication characteristics as the MVA or MVA-BN to which itrefers, but exhibiting differences in one or more parts of theirgenomes. Viruses having the same “replication characteristics” as thedeposited virus are viruses that replicate with similar amplificationratios as the deposited strain in CEF cells and the cell lines HaCat(Boukamp et al. (1988), J Cell Biol 106: 761-771), the human boneosteosarcoma cell line 143B (ECACC No. 91112502), the human embryokidney cell line 293 (ECACC No. 85120602), and the human cervixadenocarcinoma cell line HeLa (ATCC No. CCL-2). Tests and assay todetermine these properties of MVA, its derivatives and variants are wellknown to the skilled person, such as the cell line permissivity assay asdescribed in WO 02/42480. In an exemplary cell line permissivity assay,mammalian cell lines are infected with the parental and derivative orvariant MVA virus at a low multiplicity of infection per cell, i.e.,0.05 infectious units per cell (5×10⁴ TCID₅₀). Following absorption of 1hour the virus inoculum is removed and the cells washed three times toremove any remaining unabsorbed viruses. Fresh medium supplemented with3% FCS is added and infections are left for a total of 4 days (at 37°C., 5% CO₂) where viral extracts can be prepared. The infections arestopped by freezing the plates at −80° C. for three times. Virusmultiplication and cytopathic effects (CPE) are subsequently determinedon CEF cells using methods well known to the skilled person such asthose described in Carroll and Moss (1997), Virology 238, 198-211.

More specifically, MVA-BN or a derivative or variant of MVA-BNpreferably has the capability of reproductive replication in chickenembryo fibroblasts (CEF), but no capability of reproductive replicationin the human keratinocyte cell line HaCat (Boukamp et al (1988), J. CellBiol. 106:761-771), the human bone osteosarcoma cell line 143B (ECACCDeposit No. 91112502), the human embryo kidney cell line 293 (ECACCDeposit No. 85120602), and the human cervix adenocarcinoma cell lineHeLa (ATCC Deposit No. CCL-2). Additionally, a derivative or variant ofMVA-BN has a virus amplification ratio at least two fold less, morepreferably three-fold less than MVA-575 in Hela cells and HaCaT celllines. Tests and assays for these properties of MVA variants aredescribed in WO 02/42480 or in the exemplary cell line permissivityassay as described above.

The term “not capable of reproductive replication” or “no capability ofreproductive replication” is, for example, described in WO 02/42480,which also teaches how to obtain MVA having the desired properties asmentioned above. The term applies to a virus that has a virusamplification ratio at 4 days after infection of less than 1 using theassays described in WO 02/42480 or in U.S. Pat. No. 6,761,893.

The term “fails to reproductively replicate” refers to a virus that hasa virus amplification ratio at 4 days after infection of less than 1.Assays described in WO 02/42480 or in U.S. Pat. No. 6,761,893 areapplicable for the determination of the virus amplification ratio.

The amplification or replication of a virus is normally expressed as theratio of virus produced from an infected cell (output) to the amountoriginally used to infect the cell in the first place (input) referredto as the “amplification ratio.” An amplification ratio of “1” definesan amplification status where the amount of virus produced from theinfected cells is the same as the amount initially used to infect thecells, meaning that the infected cells are permissive for virusinfection and reproduction. In contrast, an amplification ratio of lessthan 1, i.e., a decrease in output compared to the input level,indicates a lack of reproductive replication and therefore attenuationof the virus.

The recombinant poxvirus vectors provided herein can be generated byroutine methods known in the art. Methods to obtain recombinantpoxviruses or to insert exogenous coding sequences into a poxviralgenome are well known to the person skilled in the art. For example,methods for standard molecular biology techniques such as cloning ofDNA, DNA and RNA isolation, Western blot analysis, RT-PCR and PCRamplification techniques are described in Molecular Cloning, Alaboratory Manual (2nd Ed.) [J. Sambrook et al., Cold Spring HarborLaboratory Press (1989)], and techniques for the handling andmanipulation of viruses are described in Virology Methods Manual [B. W.J. Mahy et al. (eds.), Academic Press (1996)]. Similarly, techniques andknow-how for the handling, manipulation and genetic engineering of MVAare described in Molecular Virology: A Practical Approach [A. J. Davison& R. M. Elliott (Eds.), The Practical Approach Series, IRL Press atOxford University Press, Oxford, UK (1993)(see, e.g., Chapter 9:Expression of genes by Vaccinia virus vectors)] and Current Protocols inMolecular Biology [John Wiley & Son, Inc. (1998)(see, e.g., Chapter 16,Section IV: Expression of proteins in mammalian cells using vacciniaviral vector)].

For the generation of the various recombinant poxviruses disclosedherein, different methods are applicable. The DNA sequence to beinserted into the virus can be placed into an E. coli plasmid constructinto which DNA homologous to a section of DNA of the poxvirus has beeninserted. Separately, the DNA sequence to be inserted can be ligated toa promoter. The promoter-gene linkage can be positioned in the plasmidconstruct so that the promoter-gene linkage is flanked on both ends byDNA homologous to a DNA sequence flanking a region of poxviral DNAcontaining a non-essential locus. The resulting plasmid construct can beamplified by propagation within E. coli bacteria and isolated. Theisolated plasmid containing the DNA gene sequence to be inserted can betransfected into a cell culture, e.g., of chicken embryo fibroblasts(CEFs), at the same time the culture is infected with poxvirus.Recombination between homologous poxviral DNA in the plasmid and theviral genome, respectively, can generate a poxvirus modified by thepresence of foreign DNA sequences.

According to a preferred embodiment, a cell of a suitable cell cultureas, e.g., CEF cells, can be infected with a poxvirus. The infected cellcan be, subsequently, transfected with a first plasmid vector comprisinga foreign or heterologous gene or genes, such as one or more of the HIVantigen encoding nucleic acids provided in the present disclosure;preferably under the transcriptional control of a poxvirus expressioncontrol element. As explained above, the plasmid vector also comprisessequences capable of directing the insertion of the exogenous sequenceinto a selected part of the poxviral genome. Optionally, the plasmidvector also contains a cassette comprising a marker and/or selectiongene operably linked to a poxviral promoter. Suitable marker orselection genes are, e.g., the genes encoding the green fluorescentprotein, β-galactosidase, neomycin-phosphoribosyltransferase or othermarkers. The use of selection or marker cassettes simplifies theidentification and isolation of the generated recombinant poxvirus.However, a recombinant poxvirus can also be identified by PCRtechnology. Subsequently, a further cell can be infected with therecombinant poxvirus obtained as described above and transfected with asecond vector comprising a second foreign or heterologous gene or genes.In this case, this gene shall be introduced into a different insertionsite of the poxviral genome, and the second vector also differs in thepoxvirus-homologous sequences directing the integration of the secondforeign gene or genes into the genome of the poxvirus. After homologousrecombination has occurred, the recombinant virus comprising two or moreforeign or heterologous genes can be isolated. For introducingadditional foreign genes into the recombinant virus, the steps ofinfection and transfection can be repeated by using the recombinantvirus isolated in previous steps for infection and by using a furthervector comprising a further foreign gene or genes for transfection.

Alternatively, the steps of infection and transfection as describedabove are interchangeable, i.e., a suitable cell can at first betransfected by the plasmid vector comprising the foreign gene and, then,infected with the poxvirus. As a further alternative, it is alsopossible to introduce each foreign gene into different viruses,co-infect a cell with all the obtained recombinant viruses and screenfor a recombinant including all foreign genes. A third alternative isligation of DNA genome and foreign sequences in vitro and reconstitutionof the recombined vaccinia virus DNA genome using a helper virus. Afourth alternative is homologous recombination in E. coli or anotherbacterial species between a poxvirus genome cloned as a bacterialartificial chromosome (BAC) and a linear foreign sequence flanked withDNA sequences homologous to sequences flanking the desired site ofintegration in the vaccinia virus genome.

One or more nucleic acid sequences encoding at least one HIV antigenaccording to embodiments of the invention can be inserted into anysuitable part of the poxvirus or poxviral vector. In a preferred aspect,the poxvirus used for the present invention includes an MVA virus.Suitable parts of the MVA virus into which one or more nucleic acids ofthe present disclosure can be inserted include non-essential parts ofthe MVA virus.

For MVA virus, non-essential parts of the MVA genome can be intergenicregions or the known deletion sites 1-6 of the MVA genome. Alternativelyor additionally, non-essential parts of the recombinant MVA can be acoding region of the MVA genome which is non-essential for viral growth.However, the insertion sites are not restricted to these preferredinsertion sites in the MVA genome, since it is within the scope of thepresent invention that the antigens and nucleic acids and anyaccompanying promoters as described herein can be inserted anywhere inthe viral genome as long as it is possible to obtain recombinants thatcan be amplified and propagated in at least one cell culture system,such as Chicken Embryo Fibroblasts (CEF cells).

Preferably, the nucleic acids of the present invention are inserted intoone or more intergenic regions (IGR) of the MVA. The terms “intergenicregion” and “IGR” refer preferably to those parts of the viral genomelocated between two adjacent open reading frames (ORF) of the MVAgenome, preferably between two essential ORFs of the MVA virus genome.For MVA, in certain embodiments, the IGR is selected from IGR 07/08, IGR44/45, IGR 64/65, IGR 88/89, IGR 136/137, and IGR 148/149. In morepreferred embodiments, the nucleic acids of the present invention areinserted in the IGR 44/45 and IGR 88/89 regions.

According to embodiments of the invention, and as noted above, any ofthe synthetic HIV envelope proteins and/or HIV antigens described hereincan be expressed in the vectors of the invention. In view of thedegeneracy of the genetic code, the skilled person is well aware thatseveral nucleic acid sequences can be designed that encode the sameprotein, according to methods entirely routine in the art. The nucleicacid encoding the synthetic HIV envelope protein and/or HIV antigens canoptionally be codon-optimized to ensure proper expression in the treatedhost (e.g., human). Codon-optimization is a technology widely applied inthe art. Some non-limiting examples of sequences encoding a syntheticHIV envelope protein of the invention are provided in SEQ ID NOs: 26(used in adenovirus vectors in the examples), and 41 (used in MVAvectors in the examples); and some non-limiting examples of sequencesencoding further HIV antigens for use in the invention are provided inSEQ ID NOs: 20-22 (used in adenovirus vectors in the examples), and38-40 (used in MVA vectors in the examples).

The invention also provides cells, preferably isolated cells, comprisingany of the vectors described herein. The cells can be used forrecombinant protein production, or for the production of viralparticles.

Also disclosed is a method of making a synthetic HIV antigenicpolypeptide. The method comprises transfecting a host cell with anexpression vector comprising nucleic acid encoding the synthetic HIVantigenic polypeptide operably linked to a promoter, growing thetransfected cell under conditions suitable for expression of thesynthetic HIV antigenic polypeptide, and isolating the synthetic HIVantigenic polypeptide from the cell. The synthetic HIV antigenicpolypeptide can be isolated or collected from the cell by any methodknown in the art including affinity chromatography, etc. Techniques usedfor recombinant protein expression are well known to one of ordinaryskill in the art in view of the present disclosure.

The invention also relates to a method for manufacturing a vectorencoding a synthetic HIV antigenic polypeptide of the invention, themethod comprising culturing a cell that comprises the vector, topropagate and multiply the vector during said culturing, and isolatingthe vector that encodes the synthetic HIV antigenic polypeptide of theinvention from the cell culture, e.g. from the cells, from the culturemedium, or both. The vector can be further purified according to methodsknown in the art.

In certain embodiments, the invention provides a poxvirus vector,preferably an MVA vector, such as an MVA-BN vector, comprising a nucleicacid sequence encoding a synthetic HIV antigen. The poxvirus vectorcomprises nucleic acid sequence encoding a synthetic HIV envelope (Env)antigen according to the invention, such as that comprising the aminoacid sequence of SEQ ID NO: 18, and optionally further comprises nucleicacid sequence encoding at least one additional HIV antigen. In preferredembodiments, the poxvirus vector and more preferably a MVA vector,comprises nucleic acid sequence encoding a first HIV Env antigen whichis a synthetic HIV Env antigen comprising the amino acid sequence of SEQID NO: 18, and at least one additional HIV antigen, such as Gag, Pol,and/or Env antigens, preferably one or more additional HIV antigenscomprising the amino acid sequences selected from the group consistingof SEQ ID NOs: 1-5, 28, and 29.

For example, in a particular embodiment, a poxvirus vector can comprisenucleic acid encoding a first HIV Env antigen comprising the amino acidsequence of SEQ ID NO: 18; a second HIV Env antigen different than thefirst HIV Env antigen; a third antigen and a fourth antigen, being twodifferent HIV Gag antigens; and a fifth antigen and a sixth antigen,being two different HIV Pol antigens. The Gag and Pol antigens can befused into a first Gag-Pol fusion antigen and a second Gag-Pol fusionantigen, such as those Gag-Pol fusion antigens comprising the amino acidsequence of SEQ ID NO: 28 or SEQ ID NO: 29.

In certain exemplary embodiments, the poxvirus vector comprises nucleicacid encoding one or more amino acid sequences selected from the groupconsisting of SEQ ID NOs: 1-5, 18, 28, and 29. In one or more specificembodiments, the poxvirus vector comprises nucleic acid encoding theamino acid sequences of SEQ ID NOs: 1-5, and 18, more preferably SEQ IDNOs: 5, 18, 28, and 29.

In other certain exemplary embodiments a vector is an adenovirus vectorcomprising a nucleic acid sequence selected from the group consisting ofSEQ ID NOs: 25, 26 and 27, preferably SEQ ID NO: 26. Further exemplaryembodiments include adenovirus vectors encoding other HIV antigens, suchadenovirus vectors comprising one or more nucleic acid sequencesselected from the group consisting of SEQ ID NOs: 20, 21, and 22. Inother certain embodiments, the vector is a poxvirus vector, preferablyan MVA vector, more preferably MVA-BN, the vector comprising one or morenucleic acid sequences selected from the group consisting of SEQ ID NOs:38, 39, 40, and 41. In one or more specific embodiments the poxvirusvector comprises SEQ ID NOs: 38, 39, 40, and 41.

The nucleic acid sequence encoding the one more HIV antigens can beinserted into any appropriate insertion site of the poxvirus vectorgenome as described herein. In particular embodiments wherein thepoxvirus vector is an MVA vector, such as MVA-BN or derivatives thereof,encoding one or more Gag-Pol fusion antigens, nucleic acid sequenceencoding a first Gag-Pol fusion antigen can be inserted into intergenicregion (IGR) 44/45 of the MVA genome and nucleic acid sequence encodinga second Gag-Pol fusion antigen can be inserted into IGR 88/89 of theMVA genome. Additionally, nucleic acid sequence encoding HIV Envantigens can be inserted into the IGR 44/45 and/or IGR 88/89 of the MVAgenome. In one or more specific embodiments, the poxvirus vectorcomprises nucleic acid sequence encoding a Gag-Pol fusion antigencomprising SEQ ID NO: 28 and nucleic acid sequence encoding an HIV Envantigen comprising SEQ ID NO: 5 into IGR 44/45 of the MVA genome and/ornucleic acid sequence encoding a Gag-Pol fusion antigen comprising SEQID NO: 29 and nucleic acid sequence encoding an HIV Env antigencomprising SEQ ID NO: 18 into IGR 88/89 of the MVA genome. Preferably,the Gag-Pol fusion antigens are each under control of a separatepromoter, preferably a Pr13.5 promoter, such as that shown in SEQ ID NO:42 and/or the Env antigens are each under control of a separatepromoter, preferably a PrHyb promoter, such as that shown in SEQ ID NO:43.

Compositions

In another general aspect, the invention relates to a compositioncomprising a vector comprising a nucleic acid encoding a synthetic HIVenvelope protein and a carrier. Preferably, the composition is a vaccinecomposition, which is described in greater detail below. According toembodiments of the invention, any of vectors described herein can beincluded in the composition. Preferably, the vector is a viral vector,more preferably an adenovirus vector or a poxvirus vector, and even morepreferably an adenovirus 26 vector or an MVA vector.

In one embodiment, a composition of the invention comprises a poxvirusvector, preferably an MVA vector, comprising nucleic acid sequenceencoding a synthetic HIV envelope protein comprising the amino acidsequence of SEQ ID NO: 8, SEQ ID NO: 18, or SEQ ID NO: 19, and morepreferably the amino acid sequence of SEQ ID NO: 18. In certainpreferred embodiments, the vector is an MVA-BN vector, or derivativethereof. In one or more specific embodiments, a composition of theinvention comprises a poxvirus vector, MVA vector, or MVA-BN vectorcomprising nucleic acid encoding at least a first HIV envelope antigencomprising the amino acid sequence of SEQ ID NO: 18. Most preferably,such vector further comprises nucleic acid sequence encoding: (b) asecond HIV Env antigen different from the first HIV Env antigen; (c) athird antigen and a fourth antigen, being two different HIV Gagantigens; and (d) a fifth antigen and a sixth antigen, being twodifferent HIV Pol antigens. In preferred embodiments, the second HIV Envantigen comprises the amino acid sequence of SEQ ID NO: 5, the third andfourth antigens comprise the amino acid sequence of SEQ ID NO: 1 and SEQID NO: 2, respectively; and the fifth and the sixth antigens comprisethe amino acid sequence of SEQ ID NO: 3 and SEQ ID NO: 4, respectively.In certain embodiments, the third and the fifth antigens are fused intoa first Gag-Pol fusion antigen that comprises the amino acid sequence ofSEQ ID NO: 28, and the fourth and the sixth antigens are fused into asecond Gag-Pol fusion antigen that comprises the amino acid sequence ofSEQ ID NO: 29.

According to embodiments of the invention, a composition comprising apoxvirus vector according to the invention can be used together with oneor more additional vectors encoding one or more additional HIV antigens,and/or one or more isolated HIV antigenic polypeptides. The additionalvectors and/or HIV antigenic polypeptides can be present in the samecomposition or in one or more different compositions. Preferably, theone or more additional vectors are viral vectors, such as adenovirusvectors, more preferably adenovirus 26 vectors, or poxvirus vectors,more preferably MVA vectors. The one or more additional vectors canencode any HIV antigen known to those skilled in the art in view of thepresent disclosure. Most preferably, the one or more additional vectorsare adenovirus vectors, preferably adenovirus 26 vectors, encoding oneor more HIV antigens comprising the amino acid sequences selected fromthe group consisting of SEQ ID NOs: 1-5, 18, 28, and 29.

In one aspect, the invention provides a combination vaccine comprisingone or more vectors together comprising nucleic acid sequences encoding(a) a synthetic HIV envelope protein comprising the amino acid sequenceof SEQ ID NO: 18; (b) a second HIV envelope protein, preferablycomprising the amino acid sequence of SEQ ID NO: 5; (c) a third antigenand a fourth antigen, being two different HIV Gag antigens, preferablycomprising the amino acid sequences of SEQ ID NOs: 1 and 2,respectively; and (d) a fifth antigen and a sixth antigen, being twodifferent HIV Pol antigens, preferably comprising the amino acidsequences of SEQ ID NOs: 3 and 4, respectively. In one or more specificembodiments, the third and fifth antigens are fused into a first Gag-Polfusion antigen, preferably comprising the amino acid sequence of SEQ IDNO: 28 and the fourth and sixth antigens are fused into a second Gag-Polfusion antigen that comprises the amino acid sequence of SEQ ID NO: 29.The vectors can each be in separate compositions, or they can becombined in a single composition. The multiple nucleic acids in thevector(s) are intended to be administered to one subject, which willresult in an immune response to HIV that is broader than the immuneresponse that would be obtained upon administration of either vectoralone. The multiple nucleic acid sequences could also be present on onesingle vector.

According to embodiments of the invention, the one or more vectors canbe adenovirus vectors, preferably adenovirus 26 vectors, and/or poxvirusvectors, preferably MVA vectors. The compositions comprising adenovirusand/or poxvirus vectors can optionally further comprise one or moreisolated HIV antigenic polypeptides. Any isolated HIV antigenicpolypeptide can be used in the compositions of the invention in view ofthe present disclosure. In certain preferred embodiments, the one ormore isolated HIV antigenic polypeptides comprises a polypeptidecomprising residues 30-708 of the amino acid sequence of SEQ ID NO: 7, apolypeptide comprising residues 30-724 of SEQ ID NO: 36, or acombination thereof.

In one or more specific embodiments, a combination comprises anadenovirus vector, preferably an adenovirus 26 vector, comprisingnucleic acid encoding one or more HIV antigens preferably selected fromthe group consisting of SEQ ID NOs: 1-5, 18, 28, and 29 and a poxvirusvector, preferably a MVA vector, comprising nucleic acid encoding one ormore HIV antigens preferably selected from the group consisting of SEQID NOs: 1-5, 18, 28, and 29. Preferably, one or more adenovirus vectors,preferably adenovirus 26 vectors together encode SEQ ID NOs: 1-5 and 18;and the poxvirus vector, preferably MVA vector, encodes SEQ ID NOs: 1-5and 18. The vectors can be present in one composition, or in one or moredifferent compositions.

According to certain embodiments of the invention, a composition, suchas a vaccine composition, comprises an immunogenically effective amountof a vector, such as a viral vector. As used herein, “an immunogenicallyeffective amount” or “immunologically effective amount” means an amountof a composition sufficient to induce a desired immune effect or immuneresponse in a subject in need thereof. In one embodiment, animmunogenically effective amount means an amount sufficient to induce animmune response in a subject in need thereof. In another embodiment, animmunogenically effective amount means an amount sufficient to produceimmunity in a subject in need thereof, e.g., provide a protective effectagainst a disease such as a viral infection. An immunogenicallyeffective amount can vary depending upon a variety of factors, such asthe physical condition of the subject, age, weight, health, etc.; theparticular application, whether inducing immune response or providingprotective immunity; the specific recombinant vector administered; theimmunogen or antigenic polypeptide encoded by the recombinant vectoradministered; the specific antigenic polypeptide administered; and theparticular disease, e.g., viral infection, for which immunity isdesired. An immunogenically effective amount can readily be determinedby one of ordinary skill in the art in view of the present disclosure.

As general guidance, an immunogenically effective amount when used withreference to a recombinant viral vector such as an adenoviral vector canbe for instance about 10⁸ viral particles to about 10¹² viral particles,for example 10⁸, 10⁹, 10¹⁰, 10¹¹, or 10¹² viral particles. A single doseof adenoviral vectors for administration to humans in certainembodiments is between 10′ and 10¹¹ viral particles. An immunogenicallyeffective amount when used with reference to a recombinant viral vectorsuch as a poxviral vector can be for instance about 10⁴ to 10¹¹ TCID₅₀,10⁵ to 10¹⁰ TCID₅₀, 10⁶ to 10⁹ TCID₅₀, or 10⁷ to 10⁸ TCID₅₀, such as10⁴, 10⁵, 10⁶, 10⁷, 10⁸, 10⁹, 10¹⁰, or 10¹¹ TCID₅₀. A preferred dose forthe subjects (preferably a human) comprises 10⁵ to 10¹⁰ TCID₅₀,including a dose of 10⁵ TCID₅₀, 10⁶ TCID₅₀, 10⁷ TCID₅₀, 10⁸ TCID₅₀, 10⁹TCID₅₀, or 10¹⁰ TCID₅₀. The immunogenically effective amount of apoxviral vector such as an MVA vector can alternatively and convenientlybe expressed in plaque forming units (pfu), and can for instance beabout 10⁵ to about 10¹¹ pfu, e.g. about 10⁵, 10⁶, 10⁷, 10⁸, 10⁹, 10¹⁰ or10¹¹ pfu, preferably about 10⁷ to 10⁹ pfu, and more preferably about 10⁸pfu, such as for instance about 0.5×10⁸, 1×10⁸, 2×10⁸, 3×10⁸, 4×10⁸, or5×10⁸ pfu. In certain embodiments, the immunogenically effective amountof an MVA vector according to the invention administered to a humansubject is about 1×10⁷ to 1×10⁹ pfu, preferably about 1×10⁸ pfu,preferably in a volume of 0.1 mL to 1 mL, e.g. 0.5 mL.

An immunogenically effective amount of a vector, such as an MVA vectorand/or adenovirus vector, can be administered in a single composition,or in multiple compositions, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10compositions (e.g., tablets, capsules or injectables), wherein theadministration of the multiple capsules or injections collectivelyprovides a subject with the immunogenically effective amount. It is alsopossible to administer an immunogenically effective amount to a subject,and subsequently administer another dose of an immunogenically effectiveamount to the same subject, in a so-called prime-boost regimen. Furtherbooster administrations can optionally be added to the regimen, asneeded. This general concept of a prime-boost regimen is well known tothe skill person in the vaccine field and is described in greater detailbelow.

Compositions of the invention may further comprise a carrier. A carriercan include one or more pharmaceutically acceptable excipients such asbinders, disintegrants, swelling agents, suspending agents, emulsifyingagents, wetting agents, lubricants, flavorants, sweeteners,preservatives, dyes, solubilizers and coatings. The precise nature ofthe carrier or other material can depend on the route of administration,e.g., intramuscular, subcutaneous, oral, intravenous, cutaneous,intramucosal (e.g., gut), intranasal or intraperitoneal routes. Forliquid injectable preparations, for example, suspensions and solutions,suitable carriers and additives include water, glycols, oils, alcohols,preservatives, coloring agents and the like. For solid oralpreparations, for example, powders, capsules, caplets, gelcaps andtablets, suitable carriers and additives include starches, sugars,diluents, granulating agents, lubricants, binders, disintegrating agentsand the like. For nasal sprays/inhalant mixtures, the aqueoussolution/suspension can comprise water, glycols, oils, emollients,stabilizers, wetting agents, preservatives, aromatics, flavors, and thelike as suitable carriers and additives.

Compositions of the invention can be formulated in any matter suitablefor administration to a subject to facilitate administration and improveefficacy, including, but not limited to, oral (enteral) administrationand parenteral injections. The parenteral injections include intravenousinjection or infusion, intra-arterial injection, subcutaneous injection,intramuscular injection, and intra-articular injection. Compositions ofthe invention can also be formulated for other routes of administrationincluding transmucosal, ocular, rectal, long acting implantation,sublingual administration, under the tongue, from oral mucosa bypassingthe portal circulation, inhalation, or intranasal.

According to certain embodiments of the invention, a compositioncomprises an immunogenically effective amount of purified or partiallypurified vector, for instance adenovirus vector, such as an adenovirus26 vector, or poxvirus vector, such as MVA or MVA-BN, the vectorcomprising a nucleic acid encoding a synthetic HIV envelope protein ofthe invention and optionally one or more additional HIV antigens. Saidcompositions can be formulated as a vaccine (also referred to as an“immunogenic composition”) according to methods well known in the art.

In certain embodiments of the invention, a composition can furthercomprise one or more polypeptides comprising an immunogenicallyeffective amount of an isolated HIV antigenic polypeptide. In general,when used with reference to a polypeptide, such as an isolated antigenicpolypeptide, an immunogenically effective amount can range from, e.g.about 0.3 to about 3000 microgram (μg), e.g. 1-1000 μg, e.g. 10-500 μg,e.g. about 50 or 250 μg. As a non-limiting example, it is possible tocombine administration of the one or more vectors encoding the syntheticHIV Env antigen of the invention (e.g., having SEQ ID NO: 18) andoptionally one or more additional HIV antigens (e.g., having SEQ ID NOs:1-5, 28, and/or 29) with administration of an isolated HIV Envpolypeptide, e.g. 250 μg of HIV clade C Env trimer protein having aminoacids 30-708 of SEQ ID NO: 7 or 250 μg of HIV mosaic Env trimer proteinhaving amino acids 30-708 of SEQ ID NO: 36.

In some embodiments, compositions of the invention can furtheroptionally comprise an adjuvant to enhance immune responses. The terms“adjuvant” and “immune stimulant” are used interchangeably herein, andare defined as one or more substances that cause stimulation of theimmune system. In this context, an adjuvant is used to enhance an immuneresponse to the vectors encoding synthetic HIV envelope proteins of theinvention and optionally one or more additional HIV antigens and/or HIVantigenic polypeptides used in combination with vectors encodingsynthetic HIV envelope proteins of the invention and optionally one ormore additional HIV antigens.

Adjuvants suitable for use with the invention should be ones that arepotentially safe, well tolerated and effective in people, such as forinstance QS-21, Detox-PC, MPL-SE, MoGM-CSF, TiterMax-G, CRL-1005, GERBU,TERamide, PSC97B, Adjumer, PG-026, GSK-I, GcMAF, B-alethine, MPC-026,Adjuvax, CpG ODN, Betafectin, aluminum salts (e.g. AdjuPhos), Adjuplex,and MF59. The optimal ratios of each component in the formulation can bedetermined by techniques well known to those skilled in the art in viewof the present disclosure.

In a preferred embodiment, the adjuvant is an aluminum salt, such asaluminum phosphate, e.g. AdjuPhos. In certain embodiments, the aluminumphosphate is preferably present in or administered with a compositionwith isolated HIV antigenic polypeptide, such as gp140.

The preparation and use of immunogenic compositions are well known tothose of ordinary skill in the art. Liquid pharmaceutical compositionsgenerally include a liquid carrier such as water, petroleum, animal orvegetable oils, mineral oil or synthetic oil. Physiological salinesolution, dextrose or other saccharide solution or glycols such asethylene glycol, propylene glycol or polyethylene glycol can also beincluded.

For instance recombinant adenovirus vector may be stored in the bufferthat is also used for the Adenovirus World Standard (Hoganson et al.,2002, Bioprocessing J 1: 43-8): 20 mM Tris pH 8, 25 mM NaCl, 2.5%glycerol. Another useful adenovirus formulation buffer suitable foradministration to humans is 20 mM Tris, 2 mM MgCl₂, 25 mM NaCl, sucrose10% w/v, polysorbate-80 0.02% w/v. Another formulation buffer that issuitable for recombinant adenovirus comprises 10-25 mM citrate buffer pH5.9-6.2, 4-6% (w/w) hydroxypropyl-beta-cyclodextrin (HBCD), 70-100 mMNaCl, 0.018-0.035% (w/w) polysorbate-80, and optionally 0.3-0.45% (w/w)ethanol. Obviously, many other buffers can be used, and several examplesof suitable formulations for the storage and for pharmaceuticaladministration of purified vectors are known.

An exemplary preparation and storage of poxviral vectors, including MVAand MVA-BN can be based on the experience in the preparation of poxvirusvaccines used for vaccination against smallpox, as described, forexample, in Stickl, H. et al., Dtsch. med. Wschr. 99, 2386-2392 (1974).

In an exemplary embodiment, purified poxvirus is stored at −80° C. witha titer of 5×10⁸ TCID₅₀/ml formulated in 10 mM Tris, 140 mM NaCl, pH7.7. For the preparation of vaccine shots, e.g., 10²-10⁸ particles ofthe virus can be lyophilized in phosphate-buffered saline (PBS) in thepresence of 2% peptone and 1% human albumin in an ampoule, preferably aglass ampoule. Alternatively, the vaccine shots can be prepared bystepwise, freeze-drying of the virus in a formulation. In certainembodiments, the formulation contains additional additives such asmannitol, dextran, sugar, glycine, lactose, polyvinylpyrrolidone, orother additives, such as, including, but not limited to, antioxidants orinert gas, stabilizers or recombinant proteins (e.g. human serumalbumin) suitable for in vivo administration. The ampoule is then sealedand can be stored at a suitable temperature, for example, between 4° C.and room temperature for several months. However, as long as no needexists, the ampoule is stored preferably at temperatures below −20° C.

In various embodiments involving vaccination or therapy, thelyophilisate is dissolved in 0.1 to 0.5 ml of an aqueous solution,preferably physiological saline or Tris buffer, and administered eithersystemically or locally, i.e., by parenteral, subcutaneous, intravenous,intramuscular, intranasal, intradermal, or any other path ofadministration known to a skilled practitioner. Optimization of the modeof administration, dose, and number of administrations is within theskill and knowledge of one skilled in the art.

An advantage of embodiments wherein the vector or vector combinationencodes both HIV antigens comprising SEQ ID NOs: 18 and 5, is increasedbreadth of the immune response (covering strains from clades B and C).

In certain embodiments, a composition or a vaccine combination of theinvention further comprises on the same or other vectors, nucleic acidencoding an HIV antigenic polypeptide comprising the amino acid sequenceof SEQ ID NO: 28 (mos1GagPol) and/or SEQ ID NO: 29 (mos2GagPol).

In a particular embodiment, a composition or a vaccine combination ofthe invention comprises a first adenovirus vector, preferably anadenovirus 26 vector, encoding an HIV antigen comprising the amino acidsequence of SEQ ID NO: 18, and further comprises a second adenovirusvector, preferably an adenovirus 26 vector, encoding an HIV antigencomprising the amino acid sequence of SEQ ID NO: 5, and one or moreadditional adenovirus vectors, preferably adenovirus 26 vectors,encoding one or more HIV antigens comprising the amino acid sequenceselected from the group consisting of SEQ ID NO: 28 or SEQ ID NO: 29.For example, a composition or a vaccine combination according to anembodiment of the invention can comprise four adenovirus vectors,preferably adenovirus 26 vectors, with a first vector encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18; a second vector encoding an HIV antigen comprising the aminoacid sequence of SEQ ID NO: 5; a third vector encoding a HIV antigencomprising the amino acid sequence of SEQ ID NO: 28; and a fourth vectorencoding a HIV antigen comprising the amino acid sequence of SEQ ID NO:29. Preferably, the poxvirus vector of the invention can be part of avaccine combination with those adenovirus vectors. Such poxvirus vector,preferably an MVA vector, e.g. an MVA-BN vector, in a preferredembodiment encodes each of SEQ ID NOs: 18, 5, 28 and 29.

In a particularly preferred embodiment of the invention, a compositionor a vaccine combination comprises a poxvirus vector, preferably an MVAvector, preferably MVA-BN, comprising nucleic acid sequence encoding sixdifferent HIV antigens, namely the antigens encoded by SEQ ID NO: 18(mos2S Env), SEQ ID NO: 5 (mos1 Env), SEQ ID NO: 1 (mos1 Gag), SEQ IDNO: 2 (mos2 Gag), SEQ ID NO: 3 (mos1 Pol), and SEQ ID NO: 4 (mos2 Pol),wherein SEQ ID NOs: 1 and 3 can optionally be fused (SEQ ID NO: 28;mos1GagPol) and SEQ ID NOs: 2 and 4 can optionally be fused (SEQ ID NO:29: mos2GagPol). An advantage is that only a single vector needs to bemanufactured, purified, formulated, tested, stored, shipped, andadministered for administering these six HIV antigens. Also, it is knownthat poxviral vectors, such as MVA, including MVA-BN, provide goodimmune responses against the antigens encoded therein. Moreover, theycan typically be advantageously used together with other vectorplatforms, such as with adenoviral, e.g. Ad26, vectors in prime-boostregimens to generate further improved immune responses. For example, thepoxvirus vector comprising nucleic acid sequence encoding the sixdifferent HIV antigens encoded by SEQ ID NOs: 1-5 and 18 can be usedtogether with one or more adenovirus vectors, preferably adenovirus 26vectors, encoding one or more HIV antigens encoded by SEQ ID NOs: 1-5and 18, preferably wherein the one or more adenovirus vectors togetherencode SEQ ID NOs: 1-5 and 18.

As mentioned above, in some embodiments, the composition or a vaccinecombination further comprises one or more isolated HIV antigenicpolypeptides. Any HIV antigenic polypeptide known to those skilled inthe art in view of the present disclosure can be further included in acomposition or a vaccine combination of the invention, including, butnot limited to an HIV envelope protein (e.g., gp160, gp140, gp120, orgp41), preferably a stabilized trimeric gp140 protein, such as astabilized clade C or clade A gp140 protein. In a preferred embodiment,the isolated HIV antigenic polypeptide is a stabilized HIV clade Ctrimeric gp140 protein, such as that comprising residues 30-708 of theamino acid sequence of SEQ ID NO: 7 (residues 1-29 of SEQ ID NO: 7 arein the signal sequence). An alternative or additional HIV Envpolypeptide that could be used in addition to the clade C gp140 proteinor alone, is a mosaic Env trimer protein, for instance having an aminoacid sequence as disclosed in amino acids 30-724 of SEQ ID NO: 36(corresponding to SEQ ID NO: 2 of WO 2014/107744, in which residues 1-29of SEQ ID NO: 36 are in the signal sequence). In certain embodiments,the HIV antigenic polypeptides comprise both (i) a clade C gp140 proteincomprising amino acid residues 30-708 of SEQ ID NO: 7, and (ii) a mosaicgp140 protein comprising amino acid residues 30-724 of SEQ ID NO: 36.

The invention also relates to a method of producing a composition or avaccine combination of the invention. According to embodiments of theinvention, a method of producing a composition or a combinationcomprises combining a vector comprising nucleic acid encoding thesynthetic HIV envelope protein of the invention with a carrier, andoptionally one or more additional vectors encoding one or moreadditional HIV antigenic polypeptides and/or one or more isolated HIVantigenic polypeptides. One of ordinary skill in the art will befamiliar with conventional techniques used to prepare such compositions.

Vaccine and Vaccine Combinations

Other general aspects of the invention relate to vaccines and vaccinecombinations. In certain embodiments, the compositions of the inventiondescribed herein are vaccines. As used herein, the term “vaccine” refersto a composition comprising an immunologically effective amount of anexpression vector, preferably a viral vector, encoding a synthetic HIVenvelope protein of the invention and optionally further encoding one ormore additional HIV antigens that can provide protective immunity or aprotective immune response to a subject, or to vaccinate a subject.According to embodiments of the invention, upon administration of thecomposition to a subject, the expression vector expresses the encodedsynthetic HIV envelope protein and optionally further encoded HIVantigens, and the expressed synthetic HIV envelope protein andoptionally further encoded HIV antigens are presented to the immunesystem of the subject, thereby inducing the required response to produceimmunity, or induce an immune response.

Thus, in another general aspect, the invention provides a vaccine forinducing an immune response against a human immunodeficiency virus (HIV)in a subject. According to embodiments of the invention, the vaccinecomprises a composition comprising an immunogenically effective amountof an expression vector encoding a synthetic HIV envelope proteincomprising the amino acid sequence of SEQ ID NO: 18. Preferably, theexpression vector is a viral vector, more preferably an adenovirusvector, e.g., adenovirus 26 vector, and most preferably a poxvirusvector, e.g., MVA or MVA-BN vector.

According to embodiments of the invention, vaccine compositions canfurther comprise one or more additional vectors, e.g., viral vectors,such as adenovirus vectors, preferably adenovirus 26 vectors, encodingone or more additional HIV antigenic polypeptides and/or one or moreisolated HIV antigenic polypeptides. The synthetic HIV envelope protein,additional vectors and/or one or more isolated HIV antigenicpolypeptides can be formulated in the same composition or one or moredifferent compositions in the vaccine.

The invention also relates to vaccine combinations for priming andboosting an immune response to one or more HIV clades in a subject inneed thereof using one or more vectors, optionally in combination withan isolated antigenic polypeptide. Thus, in another general aspect, theinvention provides a vaccine combination for inducing an immune responseagainst an HIV in a subject comprising:

-   -   (a) a first vaccine composition comprising an immunologically        effective amount of a poxvirus vector comprising nucleic acid        sequence encoding a first HIV Env antigen comprising the amino        acid sequence of SEQ ID NO: 18, and optionally further        comprising nucleic acid sequence encoding further HIV antigens,        preferably one or more HIV antigens comprising the amino acid        sequences selected from SEQ ID NOs: 1-5, 28, and 29; and at        least one of:    -   (b) (i) a second vaccine composition comprising an        immunogenically effective amount of one or more adenovirus        vectors encoding one or more HIV antigens comprising the amino        acid sequences selected from the group consisting of SEQ ID NOs:        1-5, 18, 28, and 29; and    -   (b) (ii) a third vaccine composition comprising one or more        polypeptides comprising an immunogenically effective amount of        an isolated HIV antigenic polypeptide, wherein the first        composition, and second and/or third composition are present in        the same composition or in one or more different compositions.

In certain embodiments thereof, the first vaccine composition comprisesan MVA vector encoding a first HIV Env antigen comprising the amino acidsequence of SEQ ID NO: 18, a second HIV Env antigen comprising the aminoacid sequence of SEQ ID NO: 5, third and fourth HIV Gag antigenscomprising the amino acid sequence of SEQ ID NO: 1 and SEQ ID NO: 2,respectively, and fifth and sixth HIV Pol antigens comprising the aminoacid sequence of SEQ ID NO: 3 and SEQ ID NO: 4, respectively. In certainembodiments, the Gag and Pol antigens of SEQ ID NOs: 1 and 3 arecombined and present as a Gag-Pol fusion antigen comprising SEQ ID NO:28, and/or the Gag and Pol antigens of SEQ ID NOs: 2 and 4 are combinedand present as a Gag-Pol fusion antigen comprising SEQ ID NO: 29.

In certain embodiments thereof, the second vaccine composition comprisesan Ad26 vector encoding an HIV antigen comprising the amino acidsequence of SEQ ID NO: 18, an Ad26 vector encoding an HIV antigencomprising the amino acid sequence of SEQ ID NO: 5, an Ad26 vectorencoding an HIV antigen comprising the amino acid sequence of SEQ ID NO:28, and an Ad26 vector encoding an HIV antigen comprising the amino acidsequence of SEQ ID NO: 29.

In certain embodiments of the invention, a vaccine combination comprisesone or more polypeptides comprising an immunogenically effective amountof an isolated HIV antigenic polypeptide. Preferably an isolated HIVantigenic polypeptide comprises residues 30-708 of the amino acidsequence of SEQ ID NO: 7, or residues 30-724 of SEQ ID NO: 36. Incertain embodiments, two isolated HIV antigenic polypeptides areadministered together in one composition, for instance a first isolatedHIV antigenic polypeptide that comprises residues 30-708 of the aminoacid sequence of SEQ ID NO: 7, and a second isolated HIV antigenicpolypeptide that comprises residues 30-724 of SEQ ID NO: 36. Theisolated HIV antigenic polypeptide can be present in a third compositionor in the first and/or second compositions. The first or secondcomposition can be administered together with the one or more isolatedHIV antigenic polypeptides, preferably gp140, for the priming and/orboosting administrations.

As used herein, the terms “co-delivery”, “co-administration” or“administered together with” refers to simultaneous administration oftwo or more components, such as a viral expression vector and anisolated antigenic polypeptide, or multiple viral expression vectors.“Simultaneous administration” can be administration of the two or morecomponents at least within the same day. When two components are“administered together with,” they can be administered in separatecompositions sequentially within a short time period, such as 24, 20,16, 12, 8 or 4 hours, or within 1 hour or less, such as essentiallysimultaneously, or they can be administered in a single composition atthe same time.

Another general aspect of the invention relates to a kit comprising avaccine combination according to an embodiment of the invention.

Other embodiments of the synthetic HIV envelope protein, expressionvectors, additional expression vectors, HIV antigens encoded by theexpression vectors, and isolated HIV antigenic polypeptide etc. that canbe used in the vaccine combinations of the invention are discussed indetail above and in the illustrative examples below.

Method for Inducing Protective Immunity Against HIV Infection

The invention also relates to a method of inducing an immune responseagainst one or more HIV clades in a subject in need thereof. The methodsdescribed herein include methods of priming and boosting an immuneresponse using one or more expression vectors optionally in combinationwith one or more isolated antigenic polypeptides.

According to embodiments of the invention, “inducing an immune response”when used with reference to the methods and compositions describedherein encompasses providing protective immunity and/or vaccinating asubject against an infection, such as a HIV infection, for prophylacticpurposes, as well as causing a desired immune response or effect in asubject in need thereof against an infection, such as a HIV infection,for therapeutic purposes, i.e., therapeutic vaccination. “Inducing animmune response” also encompasses providing a therapeutic immunity fortreating against a pathogenic agent, i.e., HIV. Typically, forprophylactic vaccination, compositions and vaccines are administered tosubjects who have not been previously infected with HIV, whereas fortherapeutic vaccination, compositions and vaccines are administered to asubject already infected with HIV. The immune response can be a cellularimmune response and/or a humoral immune response.

As used herein, the term “protective immunity” or “protective immuneresponse” means that the vaccinated subject is able to control aninfection with the pathogenic agent against which the vaccination wasdone. Usually, the subject having developed a “protective immuneresponse” develops only mild to moderate clinical symptoms or nosymptoms at all. Usually, a subject having a “protective immuneresponse” or “protective immunity” against a certain agent will not dieas a result of the infection with said agent.

As used herein, the term “therapeutic immunity” or “therapeutic immuneresponse” means that the HIV infected vaccinated subject is able tocontrol an infection with the pathogenic agent, i.e., HIV, against whichthe vaccination was done. Typically, the administration of the primerand booster vaccine compositions according to embodiments of theinvention will have a therapeutic aim to generate an immune responseagainst HIV after HIV infection or development of symptomscharacteristic of HIV infection. Preferably, the methods of theinvention are for therapeutic purposes, such as for therapeuticvaccination, in which the compositions and vaccines described herein areadministered to a subject already infected with HIV. Thus, the patientpopulation for treatment according to the methods of the inventiondescribed herein is preferably HIV-infected subjects, and morepreferably HIV-infected human subjects. The terms “HIV infection” and“HIV-infected” as used herein refer to invasion of a human host by HIV.As used herein, “an HIV-infected subject” refers to a subject in whomHIV has invaded and subsequently replicated and propagated within thehost, thus causing the host to be infected with HIV or have an HIVinfection or symptoms thereof.

In one general aspect, a method of inducing an immune response against ahuman immunodeficiency virus (HIV) in a subject comprises administeringto the subject a composition comprising an immunogenically effectiveamount of an expression vector, preferably a poxvirus vector (e.g., MVAor MVA-BN) comprising a nucleic acid sequence encoding a synthetic HIVenvelope protein comprising the amino acid sequence of SEQ ID NO: 18,and preferably encoding further HIV antigens as described herein. Any ofthe compositions described herein can be used in a method of inducing animmune response against HIV in a subject. The composition can furthercomprise one or more additional vectors, for instance adenovirus,encoding the same or one or more additional HIV antigens and/or one ormore additional isolated HIV antigenic polypeptides. It is also possibleto encode the one or more additional HIV antigens in the same vector asthe vector encoding the HIV envelope protein comprising the amino acidsequence of SEQ ID NO: 18. This is particularly suitable for poxvirusvectors such as MVA, including MVA-BN, as shown herein.

In another general aspect, a method of inducing an immune responseagainst a human immunodeficiency virus (HIV) in a subject comprisesadministering to the subject:

-   -   (a) a first vaccine comprising one or more recombinant        adenovirus vectors, preferably Ad26 vectors, encoding one or        more of SEQ ID NOs: 1, 2, 3, 4, 5, 18, 28, and 29; and    -   (b) a second vaccine comprising a poxvirus vector, preferably an        MVA vector encoding SEQ ID NO: 18 and preferably further        encoding one or more HIV antigens comprising the amino acid        sequences selected from the group consisting of SEQ ID NOs: 1-5,        28, and 29,        wherein steps (a) and (b) are conducted in either order, with        one of the steps for priming immunization and the other step for        boosting immunization.

In some embodiments, a method of inducing an immune response furthercomprises administering to the subject one or more isolated HIVantigenic polypeptides, preferably one or more HIV antigenicpolypeptides comprising (i) a polypeptide comprising residues 30-708 ofthe amino acid sequence of SEQ ID NO: 7, or (ii) a polypeptidecomprising residues 30-724 of SEQ ID NO: 36, or (iii) both polypeptides(i) and (ii). The one or more isolated HIV antigenic polypeptides can bepresent in the same composition as the first and/or second compositionor in one or more additional compositions. In a preferred embodiment,the one or more isolated HIV antigenic polypeptides is administered atabout the same time as the composition used for the boostingimmunization. In certain embodiments, the one or more isolated HIVantigenic polypeptides are present in the same composition as theboosting vaccine. In other embodiments, the one or more isolated HIVantigenic polypeptides are present in a composition separate from theboosting vaccine. In certain embodiments, the isolated HIV antigenicpolypeptide is in a composition comprising an adjuvant, for instancealuminum phosphate.

In a particular embodiment of a method of inducing an immune responseaccording to the invention, the first composition comprises anadenovirus vector, preferably an adenovirus 26 vector, encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18 and a second adenovirus vector, preferably an adenovirus 26vector, encoding an HIV antigen comprising the amino acid sequence ofSEQ ID NO: 5; the second composition comprises a poxvirus vector,preferably an MVA vector, such as an MVA-BN vector, according to theinvention comprising nucleic acid encoding the synthetic HIV antigencomprising the amino acid of SEQ ID NO: 18, and preferably furthercomprises nucleic acid sequence encoding one or more HIV antigenscomprising the amino acid sequences of SEQ ID NOs: 1-5, 28, and 29, morepreferably HIV antigens comprising the amino acid sequences of SEQ IDNOs: 5, 28, and 29; wherein the first composition is administered to thesubject one or more times for priming immunization, and the secondcomposition is administered to the subject one or more times forboosting immunization, or wherein the first composition is administeredto the subject one or more times for boosting immunization and thesecond composition is administered to the subject one or more times forpriming immunization. In preferred embodiments, the first compositionfurther comprises a third adenovirus vector, preferably an Ad26 vector,encoding an HIV antigenic polypeptide comprising the amino acid sequenceof SEQ ID NO: 28, and a fourth adenovirus vector, preferably an Ad26vector, encoding an HIV antigenic polypeptide comprising the amino acidsequence of SEQ ID NO: 29.

In another particular embodiment of a method of inducing an immuneresponse, the first composition comprises a first adenovirus vector,preferably an adenovirus 26 vector, encoding a synthetic HIV envelopeprotein comprising the amino acid sequence of SEQ ID NO: 18 and a secondadenovirus vector, preferably an adenovirus 26 vector, encoding a HIVantigenic polypeptide comprising the amino acid sequence of SEQ ID NO:5; the second composition comprises a poxvirus vector, preferably a MVAvector, more preferably MVA-BN, comprising nucleic acid sequenceencoding HIV antigens comprising the amino acid sequences of SEQ ID NOs:1-5 and 18, more preferably SEQ ID NOs: 5, 18, 28, and 29, andcombinations thereof; wherein the first composition is administered tothe subject, one or more times for priming immunization, and the secondcomposition is administered to the subject one or more times forboosting immunization, optionally together with one or more isolated HIVantigenic polypeptides; or wherein the second composition isadministered to the subject, one or more times for priming immunization,and the first composition is administered to the subject one or moretimes for boosting immunization, optionally together with one or moreisolated HIV antigenic polypeptides. In preferred embodiments, the firstcomposition further comprises a third adenovirus vector, preferably anAd26 vector, encoding a HIV antigenic polypeptide comprising the aminoacid sequence of SEQ ID NO: 28, and a fourth adenovirus vector,preferably an Ad26 vector, encoding a HIV antigenic polypeptidecomprising the amino acid sequence of SEQ ID NO: 29.

Administration of the immunogenic compositions comprising the expressionvectors and/or antigenic polypeptides is typically intramuscular,intradermal or subcutaneous. However, other modes of administration suchas intravenous, rectal, cutaneous, oral, nasal, etc. can be envisaged aswell. Intramuscular administration of the immunogenic compositions canbe achieved by using a needle to inject a suspension of the expressionvectors, e.g. adenovirus vectors, and/or antigenic polypeptides. Analternative is the use of a needleless injection device to administerthe composition (using, e.g., Biojector™) or a freeze-dried powdercontaining the vaccine.

For intramuscular, intravenous, cutaneous or subcutaneous injection, orinjection at the site of affliction, the vector will be in the form of aparenterally acceptable aqueous solution which is pyrogen-free and hassuitable pH, isotonicity and stability. Likewise, the isolated antigenicpolypeptide will be in the form of a parenterally acceptable solutionhaving a suitable pH, isotonicity, and stability. Those of ordinaryskill in the art are well able to prepare suitable solutions using, forexample, isotonic vehicles such as Sodium Chloride Injection, Ringer'sInjection, Lactated Ringer's Injection. Preservatives, stabilizers,buffers, antioxidants and/or other additives can be included, asrequired. A slow-release formulation can also be employed.

Typically, administration of the vaccine compositions according toembodiments of the invention will have a therapeutic aim to generate animmune response against an HIV antigen after infection or development ofsymptoms. In other embodiments, the expression vectors, e.g., adenovirusvectors and/or poxvirus vectors, and/or HIV antigenic polypeptides canbe administered for prophylactic purposes before infection ordevelopment of symptoms.

The immunogenic compositions containing the expression vectors, e.g.,adenovirus vectors and/or poxvirus vectors, and/or antigenicpolypeptides are administered to a subject, giving rise to an anti-HIVimmune response in the subject. An amount of a composition sufficient toinduce a detectable immune response is defined to be an “immunogenicallyeffective dose” or “immunogenically effective amount.” In a typicalembodiment of the invention, the immune response is a therapeutic immuneresponse.

The actual amount administered, and rate and time-course ofadministration, will depend on the nature and severity of what is beingtreated. Prescription of treatment, e.g., decisions on dosage etc., iswithin the responsibility of general practitioners and other medicaldoctors, or in a veterinary context a veterinarian, and typically takesaccount of the disorder to be treated, the condition of the individualpatient, the site of delivery, the method of administration and otherfactors known to practitioners. Examples of the techniques and protocolsmentioned above can be found in Remington's Pharmaceutical Sciences,16th edition, Osol, A. ed., 1980.

Following production of adenovirus vectors and/or poxvirus vectors suchas MVA vectors and optional formulation of such particles intocompositions, the vectors can be administered to an individual,particularly a human or other primate. Delivery to a non-human mammalneed not be for a therapeutic purpose, but can be for use in anexperimental context, for instance in investigation of mechanisms ofimmune responses to the synthetic HIV envelope protein and other HIVantigens expressed by the adenovirus vectors and/or poxvirus vectors ofthe invention.

In one embodiment of the disclosed methods, one or more adenovirusvectors encoding one or more HIV antigens disclosed herein are used toprime the immune response. One or more isolated HIV antigenicpolypeptides can be used together with the one or more adenovirusvectors for the priming immunization. In another embodiment, one or morepoxviral vectors, preferably MVA or MVA-BN, the poxviral vectorsencoding one or more HIV antigens of the present invention are used toprime the immune response. One or more isolated HIV antigenicpolypeptides can be used together with the one or more poxviral vectorsfor the priming immunization. The priming immunization can beadministered only once, but can optionally also be administered multipletimes, for example, initial priming administration at time 0, followedby another priming administration about 1-24 weeks after the initialpriming administration. One or more isolated HIV antigenic polypeptidesoptionally together with one or more additional adenovirus or poxvirusvectors encoding one or more additional HIV antigens can be used toboost the immune response.

Following the priming administration, one or more of the adenoviralvectors of the present invention or the poxviral vectors of the presentinvention can be used in one or more boosting immunizations. A boostingimmunization can also be administered once or multiple times, forexample, first at about 4-52 weeks after the initial primingadministration, optionally followed by another boosting administrationat for instance about 8-100 weeks after the initial primingadministration. In certain other embodiments, one or more adenovirusvectors of the present invention are administered together with one ormore poxviral vectors of the present invention for the priming and/orboosting immunization. The immune response induced by the immunizationis monitored.

Prime-boost regimens are generally preferred for generation of strongimmune responses. It is possible to administer the same vector multipletimes, referred to as homologous prime-boost. It is typically preferredaccording to the invention to apply a heterologous prime-boost regimen,which in this context indicates that the priming and boosting vectorsare different. In certain such heterologous prime-boost regimenembodiments for instance, the priming is with adenoviral vector, e.g.Ad26, and boosting is with poxviral vector, e.g. MVA, for instanceMVA-BN. In other such heterologous prime-boost regimen embodiments forinstance, the priming is with poxviral vector, e.g. MVA, such as MVA-BN,and boosting is with adenoviral vector, e.g. Ad26. Optionally inprime-boost regimens, isolated HIV antigenic polypeptide such as gp140can be administered at about the same time as the priming or boostingadministration of such adenoviral or poxviral vector.

In one exemplary and non-limiting embodiment, a subject is administeredfour different adenovirus 26 vectors, together encoding HIV antigenscomprising SEQ ID NOs: 5, 18, 28 and 29, wherein the vectors are presentin a 1:1:1:1 ratio and are administered at a total dose of 5×10¹⁰ viralparticles in 0.5 mL by intramuscular injection at weeks 0 and 12,followed by administration of an MVA vector encoding HIV antigenscomprising SEQ ID NOs: 5, 18, 28 and 29, at a dose of about 10⁸ plaqueforming units per 0.5 mL injection administered intramuscularly at weeks24 and 48.

It is readily appreciated by those skilled in the art that the regimenfor the priming and boosting administrations can be adjusted based onthe measured immune responses after the administrations. For example,the boosting compositions are generally administered weeks or months oreven years after administration of the priming composition.

According to embodiments of the invention, an adjuvant can beadministered together with the isolated HIV antigenic polypeptide aspart of the priming and/or boosting immunization. Any adjuvant can beused together with the isolated HIV antigenic polypeptide in view of thepresent disclosure, and in certain embodiments the adjuvant is analuminum salt, such as aluminum phosphate.

In a preferred embodiment of the invention, the adenovirus vectors usedin the methods disclosed herein include a rAd26 vector and the poxvirusvectors used in the methods disclosed herein include an MVA vector.

In one exemplary embodiment, an rAd26 vector encoding a synthetic HIVenvelope protein comprising the amino acid sequence of SEQ ID NO: 18 isused to prime the immune response in combination with an rAd26 vectorencoding an HIV antigen having the amino acid sequence of SEQ ID NO: 5.One or more additional rAd26 vectors encoding one or more additional HIVantigens having the amino acid sequences selected from the groupconsisting SEQ ID NOs: 1-4, 28 and 29 can also be administered togetherwith the other rAd26 vectors to prime the immune response. In certainembodiments, the priming administration can be re-administered beforeany boosting immunization is administered. An MVA vector encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18 and further encoding SEQ ID NOs: 5, 28, and 29 is used toboost the immune response in these embodiments. Optionally, an isolatedHIV antigenic polypeptide, such as that comprising residues 30-708 ofthe amino acid sequence of SEQ ID NO: 7, or that comprising residues30-724 of the amino acid sequence of SEQ ID NO: 36, or a combination ofat least two of such isolated HIV antigenic polypeptides, isadministered together with the MVA vector to boost the immune response.Preferably, an adjuvant is further administered with the isolated HIVantigenic polypeptide in the boosting immunization.

In another exemplary embodiment, an MVA or MVA-BN vector encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18 and further encoding SEQ ID NOs: 5, 28, and 29 is used toprime the immune response. In certain embodiments, the primingadministration is re-administered before any boosting immunization isadministered. Subsequent to the priming administration one or moreboosting immunization(s) is/are administered, the boosting immunizationcomprises an rAd26 vector encoding a synthetic HIV envelope proteincomprising the amino acid sequence of SEQ ID NO: 18 in combination withan rAd26 vector encoding an HIV antigen having the amino acid sequenceof SEQ ID NO: 5. One or more additional rAd26 vectors encoding one ormore additional HIV antigenic polypeptides having the amino acidsequences selected from the group consisting SEQ ID NOs: 1-4, 28 and 29preferably are also administered together with the other rAd26 vectorsto boost the immune response. Optionally, an isolated HIV antigenicpolypeptide, such as that comprising residues 30-708 of the amino acidsequence of SEQ ID NO: 7, or that comprising residues 30-724 of theamino acid sequence of SEQ ID NO: 36, or a combination of at least twoof such isolated HIV antigenic polypeptides, is administered togetherwith the rAd26 vectors to boost the immune response.

In a particularly exemplary embodiment, an immune response is primed byadministration of four HIV antigens encoded on adenoviral vectors,preferably rAd26 vectors, the four antigens that are encoded being: (i)a synthetic HIV envelope protein comprising the amino acid sequence ofSEQ ID NO: 18, (ii) HIV Env antigen having the amino acid sequence ofSEQ ID NO: 5, (iii) HIV Gag-Pol fusion antigen having the amino acidsequence of SEQ ID NO: 28, and (iv) HIV Gag-Pol fusion antigen havingthe amino acid sequence of SEQ ID NO: 29. Each of these four antigenscan be encoded on a separate adenoviral vector, preferably a rAd26vector, administered at a total dose of about 1, 2, 3, 4, 5, 6, 7, 8, 9,or 10×10¹⁰ viral particles (vp), e.g. about 5×10¹⁰ vp (for all vectorstogether). The vectors can be pre-mixed, e.g. in a 1:1:1:1 ratio. Theadministration of adenovirus vectors is preferably via intramuscularinjection. The priming administration can be re-administered after theinitial priming administration. In this embodiment, an immune responseis boosted by administration of an MVA or MVA-BN vector encoding fourHIV antigens comprising SEQ ID NO: 18, SEQ ID NO: 5, SEQ ID NO: 28, andSEQ ID NO: 29 at a dosage of 10⁵ to 10¹¹ pfu, e.g. a dose of 10⁷ pfu,10⁸ pfu, or 10⁹ pfu, or at a dosage of 10⁵ to 10¹⁰ TCID₅₀, e.g 10⁷, 10⁸or 10⁹ TCID₅₀. Preferably, the dosage is 2×10⁵ to 5×10⁸ pfu. Preferably,the dose for humans comprises at least 5×10⁷ pfu, e.g., at least 1×10⁸pfu, or alternatively at least 2×10⁷ TCID₅₀, at least 3×10⁷ TCID₅₀, atleast 5×10⁷ TCID₅₀, e.g. at least 1×10⁸ TCID₅₀, or at least 2×10⁸TCID₅₀. The MVA or MVA-BN administration to boost the immune responsecan be performed any time after the initial priming administration. Theboosting administration can be repeated after the initial boostingadministration. All administrations of MVA according to this embodimentcan be performed, for instance, via the intramuscular or subcutaneousroute.

Alternatively, the MVA vector can be used for priming administration andthe Ad26 vectors for boosting administration, all essentially asindicated above except in reversed order of administering the adenoviraland poxviral vector types. Optionally, isolated gp140 protein can beadministered together with boosting administration. For example,isolated Env gp140 protein, e.g. clade C gp140 protein (comprisingresidues 30-708 of the amino acid sequence of SEQ ID NO: 7), or mosaicgp140 protein (comprising residues 30-724 of the amino acid sequence ofSEQ ID NO: 36), or clade C gp140 protein and mosaic gp140 protein, at atotal dose of about 50-300 μg protein, e.g. 50 or 250 microgram of cladeC gp140 protein, or e.g. 50 or 250 microgram of mosaic gp140 protein, ore.g. 50 or 250 microgram of a combination of clade C gp140 protein andmosaic gp140 protein (e.g. in a 1:1 ratio, either mixed together orseparately administered) can be administered together with the poxvirusvector for the boosting immunization. Preferably, the gp140 protein isadministered together with an adjuvant, e.g. aluminum phosphate.

In certain embodiments, a method of inducing an immune responseaccording to the invention further comprises administering a latentviral reservoir purging agent. Cells latently infected with HIV carryintegrated virus that is transcriptionally silent, making it difficultto effectively eradicate HIV infection in treated subjects. As usedherein, “reservoir purging agent” and “latent viral reservoir purgingagent” refer to a substance that reduces the latent pool of HIV byreactivating HIV reservoirs, such as by inducing expression of quiescentHIV. Examples of latent viral reservoir purging agents suitable for usewith the invention include, but are not limited to, histone deacetylase(HDAC) inhibitors and modulators of toll-like receptors (e.g., TLR7),such as those described in WO2016/007765 and WO2016/177833, which areherein incorporated by reference in their entireties. The latent viralreservoir purging agent can be administered before, after, orco-administered with one or more of the priming and boostingimmunizations described herein. The vaccination of a combination ofadenovirus 26 vectors encoding Gag, Pol and Env antigens as a prime,followed by MVA vectors encoding such antigens as a boost, incombination with TLR7 stimulation has shown to result in improvedvirologic control and delayed viral rebound following discontinuation ofantiretroviral therapy in rhesus monkey model studies, demonstrating thepotential of therapeutic vaccination combined with innate immunestimulation to aim at functional cure for HIV infection (Borducchi E.N., et al, 2016, Nature 540: 284-287 (doi: 10/1038/nature20583)).

In certain embodiments of the invention, the priming and boostingimmunizations described herein for inducing an immune response can becombined with standard treatment, e.g., antiretroviral therapy (ART).Subjects treated according to the priming/boosting immunizations of theinvention can also undergo ART with any antiretroviral drugs known inthe art in view of the present disclosure. ART are medications thattreat HIV, although the drugs do not kill or cure the virus. However,when taken in combination they can prevent the growth of the virus. Whenthe virus is slowed down, so is HIV disease. Antiretroviral drugs arereferred to as ARV. Combination ARV therapy (cART) is referred to ashighly active ART (HAART). One of ordinary skill in the art will be ableto determine the appropriate antiretroviral treatment, frequency ofadministration, dosage of the ART, etc. so as to be compatible withadministration of the priming/boosting immunizations of the invention.

Examples of antiretroviral drugs used for ART include, but are notlimited to nucleoside reverse transcriptase inhibitors (NRTIs,non-limiting examples of which include zidovudine, didanosine,stavudine, lamivudine, abacavir, tenofovir, combivir [combination ofzidovudine and lamivudine], trizivir [combination of zidovudine,lamivudine and abacavir], emtricitabine, truvada [combination ofemtricitabine and tenofovir], and epzicom [combination of abacavir andlamivudine]), non-nucleoside reverse transcriptase inhibitors (NNRTIs,non-limiting examples of which include nevirapine, delavirdine,efavirenz, etravirine, and rilpivirine), protease inhibitors (PIs,non-limiting examples of which include saquinavir, indinavir, ritonavir,nelfinavir, amprenavir, lopinavir/ritonavir, atazanavir, fosamprenavir,tipranavir, darunavir), integrase inhibitors (INSTIs, non-limitingexamples including raltegravir, elvitegravir, and dolutegravir), andfusion inhibitors, entry inhibitors and/or chemokine receptorantagonists (FIs, CCR5 antagonists; non-limiting examples includingenfuvirtide, aplaviroc, maraviroc, vicriviroc, and cnicriviroc).

In other embodiments, subjects undergo interruption (also referred to asdiscontinuation, used interchangeably herein) of ART after completion ofa priming/boosting immunization according to embodiments of theinvention. In some embodiments, subjects can undergo antiretroviralanalytical treatment interruption (ARV ATI) after completion of apriming boosting immunization according to embodiments of the invention.“Antiretroviral analytical treatment interruption” and “ARV ATI” as usedin the invention refer to discontinuation of treatment withantiretroviral drugs in order to assess viral suppression and viremiccontrol in the absence of continued ART. Typically, subjects can undergoARV ATI, i.e., ART can be discontinued, when the subject has plasma HIVRNA levels at less than 50 copies/mL for at least about 52 weeks, but asubject can still undergo ARV ATI even if the subject has one or moreblips (i.e., instances) of plasma HIV RNA greater than 50 copies/ml toless than 200 copies/ml within this period, provided that the screeningimmediately prior to ARV ATI shows less than 50 copies/ml of plasma HIVRNA.

According to embodiments of the invention, the ART can be stopped atabout 4-20 weeks after the last booster vaccine is administered. Incertain embodiments, for subjects who are on non-nucleoside reversetranscriptase inhibitor (NNRTI)-based ART, a boosted protease inhibitorcan be administered in place of the NNRTI for about 1-2 weeks prior tostopping ART to reduce the risk of developing NNRTI resistance. It isalso possible to administer an activator (e.g. a histone deacetylaseinhibitor or TLR7 modulator) during the ATI stage to activate any (e.g.latent) HIV reservoir and thereby improve the immune response.

Subjects undergoing ARV ATI can be monitored, e.g., by measuring plasmaHIV RNA levels. For example, monitoring after the initiation of ARV ATIcan occur up to two times per week during the first six weeks whenrebound viremia is most likely to occur. “Rebound viremia” is defined asplasma HIV RNA levels of greater than 1,000 copies/ml after ARV ATI. ARTcan be re-initiated in subjects with rebound viremia. Preferably, asubject treated according to the methods of the invention will maintainviremic control after ART interruption. As used herein, “maintainviremic control” is defined as at least 24 weeks with plasma HIV RNA ofless than 50 copies/mL after ARV ATI. The “maintained viremic control”criterion is still deemed to be met if there are one or more instancesof plasma HIV RNA greater than 50 copies/ml to less than 1000 copies/ml,as long as the subject does not have plasma HIV RNA levels above 1000copies/ml on two consecutive determinations at least one week apart.

Typically (not using the methods of the instant invention) humanHIV-infected subjects have a return of viremia after 2-3 weeks followingART interruption. Without wishing to be bound by any theories, it isbelieved that the priming/boosting immunization according to embodimentsof the invention among individuals with fully suppressed HIV will resultin a measurable immune response and maintain viremic control after ARVATI in at least certain individuals. In some embodiments, subjects candiscontinue ART after being treated according to a method of theinvention. Discontinuation of ART can be for long periods of time (e.g.,at least 24 weeks, preferably longer, e.g. at least about 28, 32, 36,40, 44, 48, 52 weeks, 16 months, 18, 20, 22, 24 months, or even longer).Such periods of time in which ART is stopped or discontinued arereferred to as a “holiday” or “ART holiday” or “treatment holiday”. Inother embodiments, vaccine therapy according to the methods of theinvention can provide HIV remission, meaning that viral suppression ismaintained in the absence of ART.

EMBODIMENTS

Embodiment 1 is a poxvirus vector comprising nucleic acid encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18.

Embodiment 2 is a poxvirus vector comprising nucleic acid encoding:

-   -   (a) a first HIV envelope (Env) antigen comprising the amino acid        sequence of SEQ ID NO: 18;    -   (b) a second HIV Env antigen different from the first HIV Env        antigen;    -   (c) a third antigen and a fourth antigen, being two different        HIV Gag antigens; and    -   (d) a fifth antigen and a sixth antigen, being two different HIV        Pol antigens.

Embodiment 3 is the poxvirus vector of embodiment 2, wherein the secondHIV Env antigen comprises the amino acid sequence of SEQ ID NO: 5, thethird and fourth antigens comprise the amino acid sequence of SEQ ID NO:1 and SEQ ID NO: 2, respectively; and the fifth and the sixth antigenscomprise the amino acid sequence of SEQ ID NO: 3 and SEQ ID NO: 4,respectively.

Embodiment 4 is the poxvirus vector of embodiments 2 or 3, wherein thethird and the fifth antigens are fused into a first Gag-Pol fusionantigen that comprises the amino acid sequence of SEQ ID NO: 28, and thefourth and the sixth antigens are fused into a second Gag-Pol fusionantigen that comprises the amino acid sequence of SEQ ID NO: 29.

Embodiment 5 is the poxvirus vector of any one of embodiments 1-4,wherein the first HIV Env antigen is encoded by SEQ ID NO: 41.

Embodiment 6 is the poxvirus vector of any one of embodiments 4-5,wherein the first HIV Env antigen is encoded by SEQ ID NO: 41; thesecond HIV Env antigen is encoded by SEQ ID NO: 39; the first Gag-Polfusion antigen is encoded by SEQ ID NO: 38; and the second Gag-Polfusion antigen is encoded by SEQ ID NO: 40.

Embodiment 7 is the poxvirus vector of any one of embodiments 1-6,wherein the nucleic acid encoding the antigen(s) is operably linked to apromoter sequence.

Embodiment 8 is the poxvirus vector of any one of embodiments 1-7,wherein the poxvirus vector is a recombinant Modified Vaccinia virusAnkara (MVA) vector.

Embodiment 9 is the poxvirus vector of embodiment 8, wherein the MVAvector comprises MVA-BN or derivatives thereof.

Embodiment 10 is the poxvirus vector of embodiment 8 or 9, wherein thefirst Gag-Pol fusion antigen and the second Env antigen are insertedinto intergenic region (IGR) 44/45 of the MVA genome, and the secondGag-Pol fusion antigen and the first Env antigen are inserted into IGR88/89 of the MVA genome.

Embodiment 11 is the poxvirus vector of any one of embodiments 7-10,wherein the first Gag-Pol fusion antigen and the second Gag-Pol fusionantigens are each under control of a separate Pr13.5 promoter, and thefirst Env and the second Env antigens are each under control of aseparate PrHyb promoter.

Embodiment 12 is an isolated cell comprising the poxvirus vector of anyone of embodiments 1-11.

Embodiment 13 is a composition comprising a vector of any one ofembodiments 1-11, and a carrier.

Embodiment 14 is a vaccine comprising an immunogenically effectiveamount of a poxvirus vector according to any one of embodiments 1-11,and a pharmaceutically acceptable carrier.

Embodiment 15 is a vaccine combination, comprising:

-   -   (a) a first vaccine composition comprising an immunogenically        effective amount of a poxvirus vector, preferably a MVA vector,        according to any one of embodiments 1-11; and at least one of    -   (b) (i) a second vaccine composition comprising an        immunogenically effective amount of one or more adenovirus        vectors, preferably adenovirus 26 vectors, encoding one or more        HIV antigens, the one or more HIV antigens preferably comprising        an amino acid sequence selected from the group consisting of SEQ        ID NOs: 1-5, 18, 28, and 29; and    -   (b) (ii) a third vaccine composition comprising one or more        polypeptides comprising an immunogenically effective amount of        an isolated HIV antigenic polypeptide optionally further        comprising an adjuvant, preferably aluminum phosphate, wherein        the first composition, and second and/or third composition are        present in the same composition or in one or more different        compositions.

Embodiment 16 is the vaccine combination according to embodiment 15,wherein the one or more isolated HIV antigenic polypeptides in the thirdvaccine composition comprises (i) a polypeptide comprising residues30-708 of the amino acid sequence of SEQ ID NO: 7, or (ii) a polypeptidecomprising residues 30-724 of the amino acid sequence of SEQ ID NO: 36,or (iii) both polypeptides (i) and (ii).

Embodiment 17 is the vaccine combination of any one of embodiments15-16, wherein the second vaccine composition comprises recombinantadenovirus 26 vectors together encoding SEQ ID NOs: 1-5 and 18,preferably wherein SEQ ID NOs: 1 and 3 are fused together as SEQ ID NO:28 and/or SEQ ID NOs: 2 and 4 are fused together as SEQ ID NO: 29.

Embodiment 18 is the vaccine combination of embodiment 17, wherein thesecond vaccine composition comprise four recombinant Ad26 vectors, thefirst recombinant Ad26 vector encoding SEQ ID NO: 5; the secondrecombinant Ad26 vector encoding SEQ ID NO: 18; the third recombinantAd26 vector encoding SEQ ID NOs: 1 and 3, preferably SEQ ID NO: 28; andthe fourth recombinant Ad26 vector encoding SEQ ID NOs: 2 and 4,preferably SEQ ID NO: 29.

Embodiment 19 is a method of inducing an immune response against a humanimmunodeficiency virus (HIV) in a subject in need thereof, the methodcomprising administering to the subject the composition of embodiment13, the vaccine of embodiment 14, or the vaccine combination of any oneof embodiments 15-18.

Embodiment 20 is a composition of embodiment 13, a vaccine of embodiment14, or a vaccine combination of any one of embodiments 15-18 for use ininducing an immune response against a human immunodeficiency virus(HIV).

Embodiment 21 is a composition of embodiment 13 or a vaccine ofembodiment 14, further comprising one or more additional expressionvectors encoding one or more additional HIV antigens, and/or one or moreisolated HIV antigenic polypeptides.

Embodiment 22 is a composition of embodiment 13 or a vaccine ofembodiment 14, further comprising an adenovirus vector, preferably anadenovirus 26 vector, encoding a synthetic HIV envelope proteincomprising or consisting of the amino acid sequence of SEQ ID NO: 18.

Embodiment 23 is a composition or vaccine according to embodiment 22,further comprising a second adenovirus vector, preferably an adenovirus26 vector, encoding an HIV antigen comprising the amino acid sequence ofSEQ ID NO: 5, and optionally one or more additional adenovirus vectors,preferably adenovirus 26 vectors, encoding one or more additional HIVantigens comprising the amino acid sequences of SEQ ID NOs: 1-4, 28 and29, preferably SEQ ID NOs: 28 and 29, more preferably wherein SEQ IDNOs: 28 and 29 are encoded separately on a third and fourth adenovirusvector, preferably adenovirus 26 vectors.

Embodiment 24 is a method of producing an immune response against ahuman immunodeficiency virus (HIV) in a subject in need thereof, themethod comprising administering to the subject a composition or vaccineor vaccine combination according to any one of embodiments 13-23.

Embodiment 25 is a method of producing a composition or a vaccinecombination, comprising combining the poxvirus vector of any one ofembodiments 1-11 with a carrier, and optionally one or more additionalvectors encoding one or more additional HIV antigens and/or one or moreisolated HIV antigenic polypeptides in one or more compositions,together with a carrier. 10208f Embodiment 26 is a method of inducing animmune response against a human immunodeficiency virus (HIV) in asubject in need thereof, the method comprising administering to thesubject:

-   -   (i) a first vaccine comprising an immunogenically effective        amount of one or more recombinant adenovirus vectors, preferably        Ad26 vectors, encoding one or more HIV antigens comprising an        amino acid sequence of any one or more of SEQ ID NOs: 1-5, 18,        28, and 29, and a carrier;    -   (ii) a second vaccine comprising a poxvirus vector according to        any one of embodiments 1-11, and a carrier; and    -   (iii) optionally, a third vaccine comprising one or more        polypeptides comprising an immunogenically effective amount of        an isolated HIV antigenic polypeptides, and a carrier and        optionally further comprising an adjuvant, preferably aluminum        phosphate,        wherein steps (i) and (ii) are conducted in either order, with        one of the steps for priming immunization and the other step for        boosting immunization, and wherein the optional third vaccine is        administered together with the first composition or the second        composition for the priming and/or boosting immunization.

Embodiment 27 is a method according to embodiment 26, wherein the thirdcomposition is administered at about the same time as the compositionused for the boosting vaccine.

Embodiment 28 is a method according to embodiment 26 or 27, wherein theone or more isolated HIV antigenic polypeptides comprise (i) apolypeptide comprising residues 30-708 of the amino acid sequence of SEQID NO: 7; or (ii) a polypeptide comprising residues 30-724 of SEQ ID NO:36; or (iii) both polypeptides (i) and (ii), and wherein the one or moreisolated HIV antigenic polypeptides are in the same composition as theboosting vaccine and/or priming vaccine or in a composition separatefrom the boosting vaccine and/or priming vaccine.

Embodiment 29 is a method according to any one of embodiments 26-28,wherein (i) the first vaccine comprises an adenovirus vector, preferablyan adenovirus 26 vector, encoding a synthetic HIV envelope proteincomprising the amino acid sequence of SEQ ID NO: 18 and a secondadenovirus vector, preferably an adenovirus 26 vector, encoding a HIVantigen comprising the amino acid sequence of SEQ ID NO: 5, andoptionally one or more additional expression vectors, preferablyadenovirus vectors, more preferably adenovirus 26 vectors, encoding oneor more additional HIV antigens; (ii) the second vaccine comprises apoxvirus vector, preferably an MVA vector, encoding a synthetic HIVenvelope protein comprising the amino acid sequence of SEQ ID NO: 18 andpreferably encoding further HIV antigens comprising one or more of theamino acid sequences of SEQ ID NOs: 1-5, 28 and 29; and (iii) the thirdvaccine comprises an isolated HIV antigenic polypeptide having residues30-708 of the amino acid sequence of SEQ ID NO: 7, or residues 30-724 ofSEQ ID NO: 36; wherein the first vaccine is administered to the subjectone or more times for priming immunization, the second vaccine isadministered to the subject one or more times for boosting immunization,and the third vaccine is administered to the subject together with thesecond vaccine one or more times for the boosting immunization.

Embodiment 30 is a method according to embodiment 29, wherein the firstvaccine comprises one or more additional adenovirus 26 vectors encodingone or more HIV antigens comprising the amino acid sequences of SEQ IDNOs: 1-4, 28, and 29, preferably SEQ ID NOs: 28 and 29.

Embodiment 31 is a method according to embodiment 30, wherein the firstvaccine comprises a third adenovirus vector encoding SEQ ID NO: 28 and afourth adenovirus vector encoding SEQ ID NO: 29.

Embodiment 32 is a vaccine combination comprising the followingcomponents:

(i) an Ad26 vector encoding a synthetic HIV envelope protein comprisingthe amino acid sequence of SEQ ID NO: 18;(ii) an Ad26 vector encoding an HIV envelope protein comprising theamino acid sequence of SEQ ID NO: 5;(iii) an Ad26 vector encoding an HIV Gag-Pol fusion protein comprisingthe amino acid sequence of SEQ ID NO: 28;(iv) an Ad26 vector encoding an HIV Gag-Pol fusion protein comprisingthe amino acid sequence of SEQ ID NO: 29, and(v) an MVA vector encoding a first HIV envelope protein comprising theamino acid sequence of SEQ ID NO: 18, a second HIV envelope proteincomprising the amino acid sequence of SEQ ID NO: 5, a first Gag-Polfusion protein comprising the amino acid sequence of SEQ ID NO: 28 and asecond Gag-Pol fusion protein comprising the amino acid sequence of SEQID NO: 29.

Embodiment 33 is a vaccine combination according to embodiment 32,further comprising the following component:

(vi) (vi, a): isolated HIV antigenic polypeptide having residues 30-708of the amino acid sequence of SEQ ID NO: 7, or (vi, b): residues 30-724of the amino acid sequence of SEQ ID NO: 36, or (vi, c): both (vi, a)and (vi, b), wherein (vi, a), (vi, b), or (vi, c) optionally furthercomprise an adjuvant.

Embodiment 34 is a method of inducing an immune response against a humanimmunodeficiency virus (HIV) in a human subject in need thereof, themethod comprising: (a) administering to the subject: (i) a rAd26 vectorencoding a synthetic HIV envelope protein comprising the amino acidsequence of SEQ ID NO: 18; (ii) a rAd26 vector encoding an antigencomprising the amino acid sequence of SEQ ID NO: 5; (iii) a rAd26 vectorencoding an antigen comprising the amino acid sequence of SEQ ID NO: 28;and (iv) a rAd26 vector encoding an antigen comprising the amino acidsequence of SEQ ID NO: 29; preferably wherein the rAd26 vectors areadministered in a ratio of about 1:1:1:1 at a total dose of about1-10×10¹⁰ viral particles (vp), e.g. 5×10¹⁰ vp;

(b) optionally repeating step (a);(c) administering to the subject: (i) an MVA or MVA-BN vector comprisingnucleic acid encoding (i,a) a synthetic HIV envelope protein comprisingthe amino acid sequence of SEQ ID NO: 18; (i,b) a HIV Env antigencomprising the amino acid sequence of SEQ ID NO: 5; (i,c) a HIV Gag-Polfusion antigen comprising the amino acid sequence of SEQ ID NO: 28;(i,d) a HIV Gag-Pol fusion antigen comprising the amino acid sequence ofSEQ ID NO: 29; preferably wherein the MVA is administered at a dose of10⁵ to 10¹¹ pfu, e.g., at a dose of 10′ pfu, 10⁸ pfu, 10⁹ pfu, or 10¹⁰pfu, or at a dose of 10⁶ to 10¹⁰ TCID₅₀, e.g. between 10⁷ and 10⁹TCID₅₀; and(d) optionally repeating step (c).

Embodiment 35 is a method of inducing an immune response against a humanimmunodeficiency virus (HIV) in a human subject in need thereof, themethod comprising: (a) administering to the subject: (i) an MVA orMVA-BN vector comprising nucleic acid encoding (i,a) a synthetic HIVenvelope protein comprising the amino acid sequence of SEQ ID NO: 18;(i,b) a HIV Env antigen comprising the amino acid sequence of SEQ ID NO:5; (i,c) a HIV Gag-Pol fusion antigen comprising the amino acid sequenceof SEQ ID NO: 28; (i,d) a HIV Gag-Pol fusion antigen comprising theamino acid sequence of SEQ ID NO: 29; preferably wherein the MVA isadministered at a dose of 10⁵ to 10¹¹ pfu, e.g., at a dose of 10⁷ pfu,10⁸ pfu, 10⁹ pfu, or 10¹⁰ pfu, or at a dose of 10⁶ to 10¹⁰ TCID₅₀, e.g.between 10⁷ and 10⁹ TCID₅₀;

(b) optionally repeating step (a);(c) administering to the subject: (i) an MVA or MVA-BN vector comprisingnucleic acid encoding (i,a) a synthetic HIV envelope protein comprisingthe amino acid sequence of SEQ ID NO: 18; (i,b) a HIV Env antigencomprising the amino acid sequence of SEQ ID NO: 5; (i,c) a HIV Gag-Polfusion antigen comprising the amino acid sequence of SEQ ID NO: 28;(i,d) a HIV Gag-Pol fusion antigen comprising the amino acid sequence ofSEQ ID NO: 29; preferably wherein the MVA is administered at a dose of10⁵ to 10¹¹ pfu, e.g., at a dose of 10⁷ pfu, 10⁸ pfu, 10⁹ pfu, or 10¹⁰pfu, or at a dose of 10⁶ to 10¹⁰ TCID₅₀, e.g. between 10⁷ and 10⁹TCID₅₀; and optionally one or more of (ii, a) isolated HIV gp140 proteinhaving the sequence of amino acids 30-708 of SEQ ID NO: 7; (ii, b)isolated HIV gp140 protein having the sequence of amino acids 30-724 ofSEQ ID NO: 36; and (iii) aluminum phosphate adjuvant; wherein optionallythe isolated HIV gp140 proteins are administered in a ratio of about 1:1at a total dose of about 50-300 microgram, e.g. 250 microgram; and(d) optionally repeating step (c).

Embodiment 36 is a method of inducing an immune response against HIV ina human subject in need thereof, the method comprising:

(a) administering to the subject a MVA or MVA-BN vector encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18, SEQ ID NO: 5, SEQ ID NO: 28, and SEQ ID NO: 29, wherein theMVA or MVA-BN vector is administered at a dose of 10⁵ to 10¹¹ pfu, e.g.at a dose of 10⁷ pfu, 10⁸ pfu, 10⁹ pfu, or 10¹⁰ pfu, e.g. at a dose of2×10⁷ to 5×10⁸pfu, e.g. at a dose of about 1×10⁸ pfu, or at a dose of10⁶ to 10¹⁰ TCID₅₀, e.g. between 10⁷ and 10⁹ TCID₅₀,(b) optionally repeating step (a);(c) administering to the subject: (i) a rAd26 vector encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18; (ii) a rAd26 vector encoding an antigen comprising the aminoacid sequence of SEQ ID NO: 5; (iii) a rAd26 vector encoding an antigencomprising the amino acid sequence of SEQ ID NO: 28; (iv) a rAd26 vectorencoding an antigen comprising the amino acid sequence of SEQ ID NO: 29;and optionally one or more of: (v, a) isolated HIV gp140 protein havingthe sequence of amino acids 30-708 of SEQ ID NO: 7; (v, b) isolated HIVgp140 protein having the sequence of amino acids 30-724 of SEQ ID NO:36; (v, c) both (v, a) and (v, b); and (v, d) aluminum phosphateadjuvant; preferably wherein the rAd26 vectors are administered in aratio of about 1:1:1:1 at a total dose of about 1-10×10¹⁰ viralparticles (vp), e.g. 5×10¹⁰ vp and wherein optionally the isolated HIVgp140 proteins are administered in a ratio of about 1:1 at a total doseof about 50-300 microgram, e.g. 250 microgram; and(d) optionally repeating step (c).

Embodiment 37 is a method of inducing an immune response against HIV ina human subject in need thereof, the method comprising:

(a) administering to the subject: (i) a rAd26 vector encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18; (ii) a rAd26 vector encoding an antigen comprising the aminoacid sequence of SEQ ID NO: 5; (iii) a rAd26 vector encoding an antigencomprising the amino acid sequence of SEQ ID NO: 28; and (iv) a rAd26vector encoding an antigen comprising the amino acid sequence of SEQ IDNO: 29; preferably wherein the rAd26 vectors are administered in a ratioof about 1:1:1:1 at a total dose of about 1-10×10¹⁰ viral particles(vp), e.g. 5×10¹⁰ vp;(b) optionally repeating step (a);(c) administering to the subject (i) an MVA or MVA-BN vector encoding asynthetic HIV envelope protein comprising the amino acid sequence of SEQID NO: 18, SEQ ID NO: 5, SEQ ID NO: 28, and SEQ ID NO: 29, whereinpreferably the MVA or MVA-BN vector is administered at a dose of 10⁵ to10¹¹ pfu, e.g. at a dose of 10⁷ pfu, 10⁸ pfu, 10⁹ pfu, or 10¹⁰ pfu, e.g.at a dose of 2×10⁷ to 5×10⁸ pfu, e.g. at a dose of about 1×10⁸ pfu, orat a dose of 10⁶ to 10¹⁰ TCID₅₀, e.g. between 10⁷ and 10⁹ TCID₅₀; and(ii, a) isolated HIV gp140 protein having the sequence of amino acids30-708 of SEQ ID NO: 7; or (ii, b) isolated HIV gp140 protein having thesequence of amino acids 30-724 of SEQ ID NO: 36; or (ii, c) two isolatedHIV gp140 proteins wherein a first isolated HIV gp140 protein has thesequence of amino acids 30-708 of SEQ ID NO: 7 and a second isolated HIVgp140 protein has the sequence of amino acids 30-724 of SEQ ID NO: 36,preferably wherein these proteins are administered in a ratio of about1:1; and (iii) aluminum phosphate adjuvant; preferably wherein theisolated HIV gp140 protein is or isolated HIV gp140 proteins areadministered at a total dose of about 50-300 microgram, e.g. 250microgram; and(d) optionally repeating step (c).

Embodiment 38 is the method of any of embodiments 26-31 or 34-37,wherein the subject has been infected with HIV prior to the first stepof administering a vector or vaccine component.

Embodiment 39 is the method of any of embodiments 26-31 or 34-38,further comprising administering a latent viral reservoir purging agentto the subject.

Embodiment 40 is the method of embodiment 39, wherein the latent viralreservoir purging agent is a TLR7 modulator.

Embodiment 41 is the method of any of embodiments 26-31 or 34-40,wherein the subject is further undergoing antiretroviral therapy (ART).

Embodiment 42 is the method of embodiment 41, wherein the subjectundergoes interruption of ART after completion of a priming/boostingimmunization.

Embodiment 43 is the method of embodiment 42, wherein the interruptionof ART is initiated after completion of an Ad26 priming immunization andMVA boosting immunization, optionally wherein the MVA boostingimmunization is administered together with one or more isolated HIV Envgp140 proteins.

Embodiment 44 is a composition of any one of embodiments 13 or 21-23, avaccine of any one of embodiments 14 or 21-23, or a vaccine combinationof any one of embodiments 15-18 or 32-33, for use in treating and/orpreventing a human immunodeficiency virus (HIV) infection and/ordisease.

Embodiment 45 is a composition of any one of embodiments 13 or 21-23, avaccine of any one of embodiments 14 or 21-23, or a vaccine combinationof any one of embodiments 15-18 or 32-33, for use in manufacturing amedicament for treating and/or preventing a human immunodeficiency virus(HIV) infection and/or disease.

Embodiment 46 is use of a composition of any one of embodiments 13 or21-23, a vaccine of any one of embodiments 14 or 21-23, or a vaccinecombination of any one of embodiments 15-18 or 32-33, for manufacturinga medicament for treating and/or preventing a human immunodeficiencyvirus (HIV) infection and/or disease.

EXAMPLES Example 1: Design of HIV Envelope Antigen Sequences

Several HIV envelope antigen sequences were designed having sequencesimilarity to the mosaic HIV antigen mos2Env (SEQ ID NO: 6; previouslyalso described in WO 2010/059732). The newly designed, membrane bound,sequences were based on (a combination of) fully natural wild-typesequences from HIV envelope proteins, or a chimera of mos2Env sequenceand wild-type HIV envelope protein sequences. In addition to full lengthenvelope protein sequences (see FIG. 1A), sequences having a C-terminaltruncations of the cytoplasmic domain were also designed (see, e.g.,FIG. 1C). See also e.g., Schiernle et al., PNAS 1997; Abrahamyan et al.,J Virol 2005; Edwards et al., J Virology, 2002, 76:2683-2691. Solublevariants were also prepared by C-terminal truncation before thetransmembrane (TM) region, which was replaced by a trimerization domain,such as a GCN4 trimerization domain (see, e.g., FIG. 1B). These solublevariants were further converted into a single chain variant by mutationof the furin-cleavage site, thus inhibiting the processing of theextracellular domain of the envelope protein into gp120 and gp41subunits.

Of all constructs generated and tested, constructs based on C4 had themost optimal properties, e.g., good manufacturability, folding,immunogenicity, etc. and these were selected for further studies. Asoluble variant of the C4 construct having a GCN4 trimerization domainin place of the transmembrane domain (sC4, FIG. 1B), and a variantcomprising a 7-amino acid fragment of the cytoplasmic domain (C4D7, FIG.1C) were also generated and tested in further studies. The amino acidsequences of C4, sC4, and C4D7 are shown in SEQ ID NOs: 17, 19, and 18,respectively. Sequences encoding these are shown in SEQ ID NOs: 25, 27,and 26, respectively. Construct C1 has an extracellular domain sequencebased on the mos2Env sequence (SEQ ID NO: 6). A soluble variant ofconstruct C1 having a GCN4 trimerization domain in place of thetransmembrane domain (sC1), and a variant comprising a 7-amino acidfragment of the cytoplasmic domain (C1D7), similar to sC4 and C4D7 asshown in FIGS. 1B and 1C, respectively, were also generated. ConstructC1 and its variants were used in further studies for comparisonpurposes, since these are essentially based on the mos2Env sequence ofthe prior art. The amino acid sequences of C1, sC1 and C1D7 are shown inSEQ ID NOs: 31, 30, and 32, respectively. Nucleic acid sequencesencoding these are shown in SEQ ID NOs: 34, 33, and 35, respectively.Other constructs that were tested were less optimal than the ones basedon construct C4, and were not taken into further development.

Example 2: Expression and Folding of Synthetic HIV Envelope Proteins

The expression level, folding, and cell-surface expression of syntheticHIV envelope proteins were measured.

Expression Levels

HEK293F cells were transiently transfected with a plasmid encoding thesoluble synthetic HIV envelope proteins sC1 and sC4 as described inExample 1. Expression levels of the soluble protein were measured in thesupernatant using quantitative Western blot (QWB). The results are shownin FIG. 2. The low expression levels for sC1 (which essentiallycorresponds to mos2Env with an added transmembrane domain) are in linewith our recent insights for mos2Env. As demonstrated by the results,the sC4 variant of the invention showed significantly higher expressionlevels than the sC1 variant (control).

Protein Folding

Protein folding was tested by measuring the binding of soluble syntheticHIV envelope proteins to an antibody (MAb 17b) known to bind theco-receptor binding site of the HIV envelope protein, which is exposedonly after binding of CD4, by enzyme-linked immunosorbent assay (ELISA).In particular, binding of purified sC4 was tested for binding to MAb 17bwith prior binding of sC4 to CD4, and without prior binding of sC4 toCD4. Purified sC1 was used as a control. Binding of MAb 17b to sC4without prior CD4 binding to the envelope protein is an indication ofpartially unfolded or pre-triggered envelope protein (i.e., an unstableEnv that adopts the “open” conformation in the absence of CD4 binding).The results of the ELISA assay are shown in FIGS. 3A and 3B.

As shown in FIG. 3B, sC4 shows strong binding to MAb 17b with priorbinding to CD4, but no detectable binding to MAb 17b without priorbinding to CD4. In contrast, as shown in FIG. 3A, sC1 showed much lowerbinding to MAb 17 both with and without prior binding to CD4. Theresults suggest that sC4 has a correct folding pattern, with no exposureof the co-receptor binding site prior to CD4 binding.

Protein folding was also analyzed by native polyacrylamide gelelectrophoresis (PAGE) of sC1 and sC4 to evaluate the quaternarystructure of the soluble protein variants, and possible incorrectdisulfide bridge formation between protomers. After electrophoresis on anative gel, protein in the gel was detected by Western blot analysis. Asshown by the results in FIG. 4, the majority of sC4 is present in atrimeric state, which is the correct quaternary structure.

Taken together, the results of the protein folding experimentsdemonstrate that the sC4 soluble synthetic HIV envelope protein has thedesired folding profile, which is improved as compared to the foldingprofile of the existing mos2Env antigen (represented by sC1).

Cell Surface Expression

Cell surface expression of the membrane-bound variants of HIV envelopeproteins C1 (full length), C4 (full length, see FIG. 1A), C1D7, and C4D7was also studied. HEK293T cells were transiently transfected with onlyeGFP-encoding plasmid (negative control, NC), or with eGFP-encodingplasmid together with an expression construct encoding an HIV envelopeprotein variant. Two days post-transfection, cells were subjected tofluorescence activated cell sorting (FACS)-analysis upon exposure toseveral poly- and monoclonal antibodies directed against gp120, andsecondary antibodies, and then examined for envelope proteincell-surface expression levels. Quality of the envelope variants wasassessed by determining the overall expression levels using ananti-gp120 polyclonal antibody, and by assessing relative binding of thebroadly neutralizing antibodies PG9 and PG16, which arequaternary-structure dependent, and preferentially bind to correctlyfolded envelope trimer.

The results of the cell surface expression experiments are shown in FIG.5. The surface expression levels of truncated variants C1D7 and C4D7 asmeasured using an anti-gp120 antibody, are much higher than the surfaceexpression levels of their full length counterparts, C1 and C4,respectively. This confirms that deletion of 144 residues from thecarboxy-terminus of Env increases envelope surface expression levels.The full length C4 construct of the invention also showed improved PG9and PG16 binding as compared to full length C1, suggesting that the C4envelope sequence is properly folded (i.e., a trimer) on the cellsurface.

The results also demonstrate that the C1D7 variant, which is essentiallyMos2Env with an added transmembrane domain and 7 amino acids of thecytoplasmic domain, can be surface-expressed on HEK293T cells. This isin contrast to the soluble construct in Ad26.mos2Env, which cannot beexpressed at detectable levels on the surface when transfected to A549cells. However, relative binding to PG9 and PG16 is barely detectableabove background, suggesting that the C1D7 envelope sequence is poorlyfolded and is probably not present as an intact trimer on the cellsurface.

Overall, the C4D7 envelope variant has the most optimal antibody bindingprofile, with higher gp120 expression than its full-length counterpartC4, and with greater than 15-fold increased PG9 and PG16 bindingcompared to C1 and C1D7 (FIG. 5).

Example 3: Stability of Vectors Encoding HIV Envelope Sequences

Previous work in our laboratories (unpublished) indicated thatadenovirus 26 (Ad26) vectors encoding the mos2Env antigen sequenceshowed relatively high VP/IU ratios (indicating lower quality ofadenovirus product batches) and moreover that such vectors displayedstability issues. Accordingly, it was important to test the stability ofthe synthetic HIV envelope protein constructs of the invention in anadenovirus background.

Recombinant Ad26 (rAd26) vectors encoding HIV antigen sequences of theinvention C4, C4D7, and sC4 as described above in Example 1 weregenerated in PER.C6 cells (referred to as “rAd26.C4”, “rAd26.C4D7”, and“rAd26.sC4”, respectively). Vector clones (plaques) were picked andscaled-up for the generation of research batches. A maximum of 5 viralclones (plaques) were scaled-up to T25 format and serially passaged for10 passages in T25 format (passages 1-3 being the transfection andplaque purification steps, followed by 10 passages in T25 format,resulting in a total of 13 passages). Genetic stability was assessed atviral passage number (vpn) 3, 5, 10 and 13 by an E1 transgene cassettePCR assay, followed by sequencing at vpn 13. The results are shown inFIG. 6.

The rAd26 vectors encoding full length C4 (rAd26.C4) showed poor growthcharacteristics, as determined by no full cytopathogenic effect (CPE) in2-3 days; genetic instability, as determined by deletions of the E1transgene cassette region; or a combination thereof (FIG. 6). Due to thepoor growth characteristics and observed genetic instability, thisvector encoding full length C4 was not pursued further.

In contrast, for the rAd26 vectors encoding C4D7 (rAd26.C4D7) and sC4(rAd26.sC4), all propagated plaques remained genetically stable duringthe course of the experiment (FIG. 6). Thus, the novel sC4 and C4D7constructs outperform the original mos2Env construct with respect tostability in an adenoviral vector background. The genetic stabilitytesting up to vpn 13 represents propagation several passages beyond thatused in the industrial scale preparation of the vectors.

Example 4: Expression and In Vivo Antigenicity of HIV Envelope Sequencesin Adenovirus Vectors

Expression and antigenicity of rAd26.C4D7 and rAd26.sC4 were assessedseparately or in combination with a recombinant Ad26 vector encodingmos1Env (SEQ ID NO: 5) (hereinafter “rAd26.mos1Env”) invector-transduced A549 cells (human cell line) in vitro (data notshown). Flow cytometry analysis demonstrated that all antigens wereexpressed in cell cultures transduced with either 2×10⁴ viral particles(vp) of the single envelope antigens as controls, or with 1×10⁴ vp ofthe 2 combined Env antigens by adenovirus transduction. Alltransductions additionally contained single doses (1×10⁴ vp) ofadenovirus vectors encoding mos1GagPol (“rAd26.mos1GagPol”) andmos2GagPol (“rAd26.mos2GagPol”) (Barouch et al, Nat Med 2010,16:319-323), so that the assessed vector combinations exhibited the samerelative ratios of the different adenoviral vectors as intended forpre-clinical and clinical use. Preferably, the vectors encodingsynthetic HIV envelope proteins of the invention are combined withvectors encoding the mos1GagPol and the mos2GagPol antigens for clinicaluse.

The combination of rAd26.mos1Env and rAd26.C4D7 yielded a maximalcoverage of the assessed epitopes as determined by monoclonal antibodybinding. Particularly, the exposure of the PG16 epitope, which wascontributed by transformation with Ad26.C4D7 is promising for vaccineuse since PG16 represents a broadly neutralizing monoclonal antibodyrecognizing the V1/V2 loop region of HIV-1 Env (Walker et al, Science326:258-9, 2009). Hence, the synthetic HIV envelope protein of theinvention derived from the C4 sequence increases the breadth of theimmune response against the HIV envelope protein compared to the immuneresponse generated by mos1Env only. Vaccine-induced antibody responsesdirected towards the envelope protein region have been shown tocorrelate with protection from HIV-1 infection in the RV144 study(Haynes et al, N Engl J Med. 336:1275-86, 2012), and thus the syntheticHIV envelope protein of the invention is a promising candidate toinclude in HIV vaccine regimens.

Example 5: Immunogenicity of Vectors Encoding Synthetic HIV EnvelopeProteins

The synthetic HIV envelope protein sequences of the invention in an Ad26vector background were tested in rabbits to determine if theseconstructs were an immunogenic alternative to the rAd26.mos2Envconstruct.

The immunogenicity of adenovirus vector encoding mos1Env (rAd26.mos1Env;SEQ ID NO: 5) was tested alone, and in combination with adenovirusvectors encoding synthetic HIV envelope proteins of the invention(rAd26.C4D7 and rAd26.sC4; comprising SEQ ID NO: 8, in particular SEQ IDNOs: 18 and 19, respectively). In all cases, adenovirus 26 vectorsencoding mos1GagPol and mos2GagPol antigens (rAd26.mos1GagPol [SEQ IDNO: 28] and rAd26.mos2GagPol [SEQ ID NO: 29], respectively) were alsoadministered. More specifically, the immunogenicity of rAd26.mos1Envalone (trivalent vaccine: rAd26.mos1GagPol, rAd26.mos2GagPol andrAd26.mos1Env) was compared to the immunogenicity of rAd26.mos1Env incombination with one of rAd26.C4D7 or rAd26.sC4 (tetravalent vaccine:administration of either rAd26.mos1GagPol, rAd26.mos2GagPol,rAd26.mos1Env and rAd26.C4D7; or administration of rAd26.mos1GagPol,rAd26.mos2GagPol, rAd26.mos1Env and rAd26.sC4). This comparison of thetrivalent vaccine, which lacks any vectors encoding the synthetic HIVenvelope proteins of the invention, with the tetravalent vaccine, whichcontains vectors encoding the synthetic HIV envelope proteins of theinvention, allows for a determination of whether the HIV envelopeproteins of the invention contribute to the breadth of protection.

Administration was done in vaccine regimens, wherein these Ad26 vectorswere administered at weeks 0 and 6 as a double prime, and a clade Cgp140 protein (a trivalent Env gp140 protein having SEQ ID NO: 7 withoutthe signal peptide sequence of residues 1-29, see also WO 2010/042942)at weeks 12 and 18 as a double boost (see e.g. Barouch et al, 2015,Science 349: 320-324). Table 1 describes the vaccine regimens used forthe current study. rAd26.Empty refers to a control vector lacking anygene encoding a sequence for an HIV antigenic protein. Each groupcontained six rabbits.

TABLE 1 Vaccine regimens tested in immunogenicity study in rabbits Firstand second Immunizations Third and fourth immunizations Total Dose Groupadeno vectors Dose (vp) dose (vp) protein boost (ug) Adjuvant N= 1rAd26.Mos1Env  2.5 × 10¹⁰ 5 × 10¹⁰ GP140 (clade C) 10 AdjuPhos 250 μg 6rAd26.Mos1GagPol 1.25 × 10¹⁰ rAd26.Mos2GagPol 1.25 × 10¹⁰ 2rAd26.Mos1Env 1.25 × 10¹⁰ 5 × 10¹⁰ GP140 (clade C) 10 AdjuPhos 250 μg 6rAd26.C4D7 1.25 × 10¹⁰ rAd26.Mos1GagPol 1.25 × 10¹⁰ rAd26.Mos2GagPol1.25 × 10¹⁰ 3 rAd26.Mos1Env 1.25 × 10¹⁰ 5 × 10¹⁰ GP140 (clade C) 10AdjuPhos 250 μg 6 rAd26.sC4 1.25 × 10¹⁰ rAd26.Mos1GagPol 1.25 × 10¹⁰rAd26.Mos2GagPol 1.25 × 10¹⁰ control rAd26 Empty   5 × 10¹⁰ 5 × 10¹⁰ NA0 AdjuPhos 250 μg 6

The comparison of the trivalent Ad26 vaccine (lacking the novel Envantigens of the invention) with the tetravalent Ad26 vaccine (whichcomprises the novel sC4 or C4D7 Env antigens) allows for testing whetherthe novel antigens of the invention contribute to breadth of protection.An established TZM-bl cell-based neutralization assay [Montefiori D C.Methods Mol Biol 2009, 485:395-405; Sarzotti-Kelsoe M et al., J ImmunolMethods 2014, 409:131-146] was used to measure neutralizing activity ofthe vaccine candidates.

The results are shown in FIG. 7, and were statistically analyzed byusing the trivalent vaccine (group 1 in Table 1) as control group andcomparing to each of the novel tetravalent vaccines (groups 2 and 3 inTable 1).

Overall, the novel C4-derived (i.e. encoding Env proteins comprising SEQID NO: 8, being an alternative for mos2Env) adenovirus constructs wereimmunogenic after two homologous intramuscular immunizations in rabbits.

Neutralization capacity of rabbit immune sera against Tier 1Bpseudoviruses was absent (data not shown), which is not unexpected as itwas known that such viruses are more difficult to neutralize.

Pseudovirus neutralization capacity of rabbit immune sera against aclade B Tier 1A virus was unaffected by the addition of new components(data not shown). This demonstrates that the novel antigen did notnegatively interfere with immunogenicity of the existing clade B antigenpresent in the vaccine (although the new components were directed toclade C, such undesirable interference could not be excluded a prioribefore it had been tested).

Pseudovirus neutralization capacity of rabbit immune sera against aclade C Tier 1A virus was significantly enhanced in the quadrivalentnovel C4D7 containing adeno (quadrivalent, group 2), compared totrivalent (having only mos1Env) immunization alone (group 1) (FIG. 7panel B). In addition, pseudovirus neutralization capacity of rabbitimmune sera against a clade C Tier 1A virus at week 8 was significantlyenhanced in the tetravalent novel sC4 containing adenovirus(quadrivalent, group 3), compared to trivalent (having only mos1Env)immunization alone (group 1) (FIG. 7 panel B).

In conclusion, the C4D7 and sC4 constructs encoded in Ad26 wereimmunogenic and addition thereof expanded the binding- andneutralization capacity of a vaccine that has mos1Env (mainly clade B)as sole Ad26-encoded Env component, towards clade C strains (FIG. 7B).

Example 6: Immunogenicity of Vaccine Regimens Including Vectors EncodingSynthetic HIV Envelope Proteins of the Invention

One further rabbit study assessed the tetravalent vector combinationAd26.Mos4.HIV (consisting of four adenoviral vectors: Ad26.Mos1GagPol[encoding SEQ ID NO: 28], Ad26.Mos2GagPol [encoding SEQ ID NO: 29],Ad26.Mos1Env [encoding SEQ ID NO: 5] and Ad26.Mos2SEnv [the name “C4D7”as used above is also referred to as “Mos2S”; this vector encodes thenovel SEQ ID NO: 18 according to the invention], in a 1:1:1:1 mixture ata total dose of 5×10⁹ vp,) applied intramuscularly as double primeimmunizations in weeks 0 and 6, in combination with recombinant HIV-1Env protein boosts using clade C gp140 [having the sequence of aminoacid residues 30-708 of SEQ ID NO: 7], Mosaic gp140 [having the sequenceof amino acid residues 30-724 of SEQ ID NO: 36], or a combination ofclade C gp140 and Mosaic gp140, in weeks 13 and 19. These protein boostswere applied intramuscularly at a total dose of 10 or 50 micrograms ofprotein combined with 250 micrograms aluminum phosphate adjuvantformulated on the day of immunization.

Results indicate that all tested regimens were immunogenic in allanimals, inducing high antibody titers and moderate neutralizationactivity against Tier 1 Env pseudotyped viruses. If Mosaic gp140 wasused as vaccine antigen, either alone or in combination with clade Cgp140, Mosaic gp140-specific ELISA titers and clade B pseudovirusrecognition were significantly increased at week 15 in comparison to thereference group boosted with clade C gp140 alone. The overall effectsize of the improvement was moderate, and bigger for the group boostedwith the bivalent clade C gp140-Mosaic gp140 combination compared toMosaic gp140 alone. At week 21 of the study, these differences were lostand immune responses measured for the cohorts receiving bivalent clade Cgp140-Mosaic gp140 boosts or monovalent clade C gp140 boosts werestatistically indistinguishable.

The bivalent protein regimen showed comparable induction of clade CELISA titers and pseudovirus recognition as the clade C gp140 aloneboosted regimen, indicating that the inclusion of the clade B-relatedimmunogen Mosaic gp140 had no negative effect on clade C antigencoverage, whilst significantly enhancing clade B coverage at week 15 ofthe study.

The data confirm that the Ad26.Mos2SEnv vector encoding a synthetic Envantigen according to the invention can be successfully used in vaccineregimens.

Example 7: Construction of MVA Vectors Encoding Synthetic HIV EnvelopeProteins of the Invention in Combination with Other HIV Antigens

In the instant example, an MVA-BN vector was generated (termed“MVA-mBN414”), comprising a nucleic acid encoding the novel HIV mos2SEnvantigen described herein as SEQ ID NO: 18 (also referred to as C4D7).The MVA-mBN414 vector additionally comprised nucleic acids encoding thefollowing HIV antigens: mos1Env (SEQ ID NO: 5); mos1Gag (SEQ ID NO: 1);mos2Gag (SEQ ID NO: 2); mos1Pol (SEQ ID NO: 3); and mos2Pol (SEQ ID NO:4). In MVA-mBN414 the mos1Gag (SEQ ID NO:1) and mos1Pol (SEQ ID NO: 3)were encoded as a fusion protein (SEQ ID NO:28, “mos1GagPol”) and themos2Gag and mos2Pol were encoded as a fusion protein (SEQ ID NO: 29,“mos2GagPol”). See FIG. 8 for a schematic representation of the insertsinto regions of the MVA genome.

We designed a novel nucleic acid (SEQ ID NO: 41) coding for the HIVantigen mos2SEnv (SEQ ID NO: 18); a novel nucleic acid (SEQ ID NO: 39)coding for the HIV antigen mos1Env (SEQ ID NO: 5); a novel nucleic acid(SEQ ID NO: 38) coding for the HIV antigen mos1GagPol (SEQ ID NO: 28);and a novel nucleic acid (SEQ ID NO: 40) coding for the HIV antigenmos2GagPol (SEQ ID NO: 29). The novel nucleic acids were designed forhuman expression, minimal homology among each other, and reduced poly-ntstretches as well as repetitive elements.

The PrMVA13.5 long promoter (SEQ ID NO: 42) was included in front of theATG start codon of both the mos1GagPol and mos2GagPol antigen sequences.The PrHyb promoter (SEQ ID NO: 43) was included in front of the ATGstart codon of both the mos2SEnv and the mos1Env antigen sequences.

The mos1GagPol and mos1Env coding sequences were inserted via SacII andPad into pBNX208, a transfer vector encoding IGR 44/45 MVA-BN homologousregions, thus allowing insertion into the targeted region (IGR 44/45) ofMVA-BN via homologous recombination. Moreover, pBNX208 encodes heGFP andnptII for positive selection as well as repetitive sequences of the IGR44/45 MVA-BN homologous region Flank 2 or later excision of theselection cassette via homologous recombination in the absence ofselective pressure. The mos2GagPol and mos2Env coding sequences wereinserted via NotI into pBNX227, a transfer vector encoding IGR88/89MVA-BN homologous regions, thus allowing insertion into of the targetedregion (IGR 88/89) of MVA-BN via homologous recombination. Moreover,pBNX227 encodes mRFP1 and ecogpt for positive selection, which areflanked by two loxP sites for later excision of the selection cassettein the absence of selective pressure following transfection with aplasmid encoding the CRE-recombinase, which catalyzes the preciseexcision of nucleic acid sequences flanked by their target sequenceloxP.

The MVA based vectors were generated in primary chicken fibroblasts(CEF) and produced as described herein. The CEF cells were isolatedweekly from chicken embryos and maintained in VP-SFM medium without FBS.Briefly, CEF cells were transfected with MVA vector plasmid, usingFugene according to the instructions provided by the manufacturer(Promega) and a coinfection with MVA-BN was performed. Cells wereharvested after two or three days, sonified and further passaged. Thevirus was plaque purified in CEF cells cultured in a multi-well96-tissue culture plate following amplification within a single well ofa multi-well 12-tissue culture plate. Further amplification was carriedout in CEF cells cultured in a single well of a multiwell 6-tissue plateand subsequently in a T175 tissue culture flask.

The MVA-mBN414 is thus an MVA-BN comprising in its IGR 44/45 region anucleic acid encoding mos1GagPol (SEQ ID NO: 28) under control of aPrMVA13.5long promoter (SEQ ID NO: 42) and a nucleic acid encodingmos1Env (SEQ ID NO: 5) under control of a PrHyb promoter (SEQ ID NO:43). In the IGR 88/89 region there is a nucleic acid encoding themos2GagPol (SEQ ID NO: 29) under control of a PrMVA13.5long promoter(SEQ ID NO: 42) and a nucleic acid encoding mos2SEnv (SEQ ID NO: 18)under control of a PrHyb promoter (SEQ ID NO: 43). The MVA-mBN414 vectorwas used in subsequent experiments in prime-boost regimens withadenovirus vectors encoding antigens described herein.

Example 8: Immunogenicity of MVA-mBN414 in Rabbits

The immunogenicity of MVA-mBN414 (see Example 7) in New Zealand White(NZW) rabbits was assessed in the context of Ad26.Mos.HIV (a trivalentvaccine having 3 Ad26 vectors together encoding HIV antigens having SEQID NOs: 1, 2, 3, 4 and 5; in the form of antigens mos1GagPol (SEQ ID NO:28), mos2GagPol (SEQ ID NO: 29), and mos1Env (SEQ ID NO: 5)) prime, andin comparison to homologous prime-boost with Ad26.Mos.HIV. In addition,the added benefit of co-application of clade C gp140 protein (adjuvantedwith aluminum phosphate) at day 42 and day 62 (injection intocontra-lateral muscles (i.e., in separate limbs)) was assessed.

The immunization schedule that was used is provided in the followingTable 2:

TABLE 2 Immunization schedule for immunogenicity study in rabbitsImmunization day Immunization day N N Group 0 + 22 43 + 64 (female)(male) 1 Ad26.Mos.HIV Ad26.Mos.HIV 7 7 5 × 10¹⁰vp 5 × 10¹⁰vp 2MVA-mBN414 7 7 1.8 × 10⁸ TCID₅₀ 3 MVA-mBN414 7 7 1.8 × 10⁸ TCID₅₀ +clade C gp140 250 μg in AdjuPhos ® 425 μg 4 Ad26.Mos.HIV MVA-mBN414 7 75 × 10⁹vp 1.8 × 10⁷ TCID₅₀ + clade C gp140 25 μg in AdjuPhos ® 42.5 μg 5Ad26.Empty BN-MVA.Empty 3 3 5 × 10⁹vp 1.8 × 10⁸ TCID₅₀

The readout assays were a clade C (aa residues 30-708 of SEQ ID NO: 7)and mosaic gp140 (aa residues 30-724 of SEQ ID NO: 36) ELISA, and anHIV-1 pseudovirus neutralization assay. Neutralization capacity of serafrom immunized rabbits was tested against HIV-1 ENV pseudotyped virusparticles (EPVs) by inhibition of entry to TZM-bl cells. TZM-bl cellsexpress high levels of CD4 and the co-receptors CCR5 and CXCR4 andcontain an integrated tat-responsive Luciferase reporter gene undercontrol of an HIV long-terminal repeat sequence. A neutralizing effectof serum-containing HIV-1 Env antibodies against the EPV's results inreduced luciferase expression and thereby a reduced luminescence signalin combination with the luciferin containing substrate. Serum orantibodies were tested in a three-fold serial dilution over 6 steps,starting at 1/20. The maximal luciferase expression was measured byadding only cells+EPVs within one well without serum or antibodies. Thebackground luciferase expression was measured by adding only cells to awell, without serum/antibodies and EPVs. A non-linear 4 parameter curvewas fitted between the maximal and background luciferase signal and log10-transformed IC₅₀ values were determined as reportable value.

The results are shown in FIG. 9.

The results show that MVA-mBN414 was immunogenic in all rabbits. Therewas no obvious difference in immunogenicity between male and femaleanimals. The MVA boost in the context of Ad26 prime induced an increasein the HIV-specific humoral immune response (measurable in clade CELISA, clade B-like Mosaic ELISA and in clade B VNA) compared tohomologous Ad26 prime-boost.

Co-administration of clade C gp140 protein with MVA as a boost inducedan increase in (homologous) clade C gp140 ELISA and (heterologous)Mosaic gp140 ELISA titers compared to a boost with MVA only.

Example 9: Immunogenicity of MVA-mBN414 in Mice

The immunogenicity of MVA-mBN414 was also evaluated in CBF1 mice, withthe aim to assess the immunogenicity of a heterologous Ad26.Mos4.HIV(see Example 6) prime and MVA-mBN414 (see Example 7) boost, incomparison to a homologous MVA prime-boost (i.e. both priming andboosting with MVA-mBN414).

The immunization schedule that was used is provided in the followingTable 3:

TABLE 3 Immunization schedule for immunogenicity study in rabbits Week 0Week 5 Group Test article: Dose: Test article: Dose: N= 1 Ad26.Mos4.HIV2.5 × 10⁹ MVA-mBN414 2.8 × 10⁶ 7 total vp TCID₅₀ 2 2.5 × 10⁸ 2.8 × 10⁵ 7total vp TCID₅₀ 3 MVA-mBN414 2.8 × 10⁶ MVA-mBN414 2.8 × 10⁶ 7 TCID₅₀TCID₅₀ 4 2.8 × 10⁵ 2.8 × 10⁵ 7 TCID₅₀ TCID₅₀ 5 Ad26.Empty 2 × 10⁹ MVABN- 2.8 × 10⁶ 5 total vp empty TCID₅₀

The readout assays for humoral immune responses (antigen-specific IgGmeasurement at weeks 5 and 7) was a mosaic gp140 (aa residues 30-724 ofSEQ ID NO: 36) ELISA (see example 8). The readout assay for cellularimmune responses (at week 7) was an IFN-γ ELISPOT (assay as described inKhan et al, Int J Cancer, 2017, Mar. 6, doi: 10.1002/ijc.30679. [Epubahead of print]; 2017, Jul. 14, 141(2), 393-404), using Env, Gag and Polimmunodominant peptides as stimuli.

The results of the ELISPOT are shown in FIG. 10. An intracellularcytokine staining (ICS) assay was also performed, which gave similarresults (not shown).

The results indicate that priming with Ad26 or MVA induced detectableimmune responses at week 5 (FIG. 10A), that are further increased byboost immunization with MVA at week 7 (FIG. 10B) for both, theheterologous Ad-MVA regimen and the homologous MVA-MVA regimen.Heterologous Ad-MVA prime-boost induced significantly higher ELISAtiters than the homologous MVA-MVA prime-boost regimen. This was alsoobserved for cellular immune responses measured by ELISPOT against theantigens Env, Gag and Pol at week 7 (FIG. 10C-E). Homologous MVAprime-boost immunization induced a low but detectable cellular immuneresponse against the antigens Gag and Pol that is clearly differentiablefrom control data.

All in all, the results show that an MVA with HIV antigens according tothe invention is immunogenic. In addition, it is shown that such avector can advantageously be used in prime-boost regimens withadenoviral vectors encoding HIV antigens, and/or with isolated HIV gp140proteins.

REFERENCES

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1. A poxvirus vector comprising nucleic acid encoding: (a) a first HIVenvelope (Env) antigen comprising the amino acid sequence of SEQ ID NO:18; (b) a second HIV Env antigen different from the first HIV Envantigen; (c) a third antigen and a fourth antigen, being two differentHIV Gag antigens; and (d) a fifth antigen and a sixth antigen, being twodifferent HIV Pol antigens.
 2. The poxvirus vector of claim 1, wherein:the second HIV Env antigen comprises the amino acid sequence of SEQ IDNO: 5, the third and fourth antigens comprise the amino acid sequence ofSEQ ID NO: 1 and SEQ ID NO: 2, respectively; and the fifth and the sixthantigens comprise the amino acid sequence of SEQ ID NO: 3 and SEQ ID NO:4, respectively.
 3. The poxvirus vector of claim 1, wherein the thirdand the fifth antigens are fused into a first Gag-Pol fusion antigenthat comprises the amino acid sequence of SEQ ID NO: 28, and the fourthand the sixth antigens are fused into a second Gag-Pol fusion antigenthat comprises the amino acid sequence of SEQ ID NO:
 29. 4. The poxvirusvector of claim 1, wherein the first HIV Env antigen is encoded by SEQID NO:
 41. 5. The poxvirus vector of claim 3, wherein the first HIV Envantigen is encoded by SEQ ID NO: 41; the second HIV Env antigen isencoded by SEQ ID NO: 39; the first Gag-Pol fusion antigen is encoded bySEQ ID NO: 38; and the second Gag-Pol fusion antigen is encoded by SEQID NO:
 40. 6. The poxvirus vector of claim 1, wherein the poxvirusvector is a recombinant Modified Vaccinia virus Ankara (MVA) vector. 7.The poxvirus vector of claim 6, wherein the MVA vector comprises MVA-BNor derivatives thereof.
 8. The poxvirus vector of claim 6, wherein thefirst Gag-Pol fusion antigen and the second Env antigen are insertedinto intergenic region (IGR) 44/45 of the MVA genome, and the secondGag-Pol fusion antigen and the first Env antigen are inserted into IGR88/89 of the MVA genome.
 9. The poxvirus vector of claim 6, wherein thefirst Gag-Pol fusion antigen and the second Gag-Pol fusion antigen areeach under control of a separate Pr13.5 promoter, and the first Envantigen and the second Env antigen are each under control of a separatePrHyb promoter.
 10. A vaccine comprising a poxvirus vector according toclaim 1 and a pharmaceutically acceptable carrier.
 11. A vaccinecombination comprising: (a) a first vaccine composition comprising animmunologically effective amount of a poxvirus vector according to claim1; and at least one of: (b) (i) a second vaccine composition comprisingan immunogenically effective amount of one or more adenovirus vectorsencoding one or more of the first, second, third, fourth, fifth andsixth antigens; and (b) (ii) a third vaccine composition comprising oneor more polypeptides comprising an immunogenically effective amount ofan isolated HIV antigenic polypeptide, wherein the first composition,and second and/or third composition are present in the same compositionor in one or more different compositions.
 12. The vaccine combination ofclaim 11, wherein the second vaccine composition comprises recombinantAd26 vectors together encoding SEQ ID NOs: 18, 5, 1, 2, 3 and
 4. 13. Thevaccine combination of claim 11, wherein the one or more isolated HIVantigenic polypeptides in the third vaccine composition comprise: (i) apolypeptide comprising residues 30-708 of the amino acid sequence of SEQID NO: 7, or (ii) a polypeptide comprising residues 30-724 of SEQ ID NO:36; or (iii) both polypeptides (i) and (ii).
 14. A method of inducing animmune response against a human immunodeficiency virus (HIV) in asubject in need thereof, the method comprising administering to thesubject the vaccine of claim
 10. 15. A method of inducing an immuneresponse against a human immunodeficiency virus in a subject in needthereof, the method comprising administering to the subject: (a) a firstvaccine comprising one or more recombinant adenovirus vectors,preferably Ad26 vectors, encoding one or more of SEQ ID NOs: 1, 2, 3, 4,5 and 18; and (b) a second vaccine comprising a poxvirus vectoraccording to claim 1, wherein the first vaccine is a priming vaccine andthe second vaccine is a boosting vaccine, or wherein the second vaccineis a priming vaccine and the first vaccine is a boosting vaccine. 16.The method of claim 15, further comprising administering to the subjectone or more isolated HIV antigenic polypeptides, at about the same timeas the boosting vaccine, wherein the one or more HIV antigenicpolypeptides preferably comprise (i) a polypeptide comprising residues30-708 of the amino acid sequence of SEQ ID NO: 7, or (ii) a polypeptidecomprising residues 30-724 of SEQ ID NO: 36; or (iii) both polypeptides(i) and (ii), and wherein the one or more isolated HIV antigenicpolypeptides is in the same composition as the boosting vaccine or in acomposition separate from the boosting vaccine.
 17. The method accordingto claim 14 wherein the subject is a subject that has been infected withHIV.
 18. A method of inducing an immune response against a humanimmunodeficiency virus (HIV) in a subject in need thereof, the methodcomprising administering to the subject the vaccine combination of claim11.
 19. A method of inducing an immune response against a humanimmunodeficiency virus (HIV) in a subject in need thereof, the methodcomprising administering to the subject the vaccine combination of claim12.
 20. A method of inducing an immune response against a humanimmunodeficiency virus (HIV) in a subject in need thereof, the methodcomprising administering to the subject the vaccine combination of claim13.